The most important book ever written on presidential impeachment is only 69 pages long. Charles Black, Jr.,’s Impeachment: A Handbook was published in the summer of 1974, at the height of the Watergate crisis, and reissued in October 1998, two months before Bill Clinton became the second president in U.S. history to be impeached.

If the pattern holds, the book could enjoy a third printing under the Trump presidency. But I wouldn’t want to prematurely speculate on the point. Black too persuasively urges against it.

“Black’s words are cool, not hot,” Akhil Amar explains in the foreword to the second edition. Written for the lay public, this famously lucid handbook is a model of dispassionate constitutional reasoning, guiding the citizen reader through the thorny legal questions that together add up to the most serious choice our democratic republic can make: whether to remove from our highest office the individual whose election, along with that of his vice president, constitutes “the only political act that we perform together as a nation.”

Today marks the first time the core chapter of Black’s book—on what he called the “heart of the matter”—is available in its entirety online. We are providing this resource because amidst a tidal wave of 140-character screeds, Black’s analysis of what actually constitutes “the impeachable offense” is pure signal in the noise.

Last month I made a pragmatic argument against pushing too early for Trump’s impeachment. But as Black makes clear, hasty action on this front is more fundamentally a failure of principle. “Everyone must shrink from this most drastic of measures,” he declares on page one. Acknowledging his own status as a longtime political opponent of then-President Richard Nixon, Black nonetheless expresses “a very strong sense of the dreadfulness of the step of removal.” Impeachment must be treated like high-risk surgery, he insists, “to be resorted to only when the rightness of diagnosis and treatment is sure.”

This, the first of two themes that shape the book’s outlook, could go a long way in grounding our own approach to the developments, serious or salacious, weekly rocking the Trump presidency. Black emphasizes that the process by which impeachment is considered and pursued must be as free as possible from political pressures. This might seem hopelessly idealistic: in the immortal words of then-Congressman Gerald Ford in 1970, an "impeachable offense" is whatever a majority of the House “considers it to be at a given moment in history." But in Black’s hands, the commitment to principles over politics is not a naive abstraction but a duty that comes with a constitutional blueprint. He breaks down the key issues with an analytical acuity that also serves as an ennobling mechanism: conceding what the process lacks in sure answers, Black derives a set of principles that remind us that an honorable approach is possible even when consensus on the outcome is not.

A second theme: Black deploys his trademark interpretive mode—what legal scholars call structuralism—to derive from the architecture of the Constitution, from the relationships and institutions it ordains, a set of clear-headed insights for questions that go unanswered in the text. These inferences have a distinctly pragmatic cast. This is because the Constitution must be construed in accordance with the Framers’ intent that it be “workable and reasonable,” says Black. This might seem like an obvious intuition, but Black deploys it with the care and discretion necessary to raise a coherent and persuasive body of knowledge from what might otherwise be easily reduced to a bag of bones.

With an eye to these larger principles, let’s walk through the four major sections of Black’s guide, reshuffled to reflect the order of our concerns. My purpose here is to zero in on the key points worth understanding under any presidency and to flesh out some of their implications for this one.

As I see it, this is a walk with a view: impeachment is the ripping of a compromised sail from the mast of our ship, on an infinite sea. It is nothing to celebrate and no better than a crime against our collective vessel, an act of barratry, when pursued for the wrong reasons. In the rare case, presidential impeachment is a necessary effort at course-correction—but it also involves a measure of violence from which our constitutional democracy can only slowly and by no means inevitably recover.

So let’s be cool, not hot.

The Impeachable Offense

The central inquiry: “What offenses are impeachable?”

The Constitution provides that the president, like the vice president and all civil officers of the United States, “shall be removed from Office on Impeachment for and Conviction of, Treason, Bribery, or other high Crimes and Misdemeanors.” In unpacking this phrase, consider first what Black consciously does not.

Impeachment—from the Latin impedicāre, to fetter, to entangle—is a process that the Framers did not merely export from the Brits but rescued from a withering vine. The Constitutional Convention began just as Parliament plunged into impeachment proceedings against Warren Hastings, the first of the British governors-general of India. What unfolded was an exhausting, seven-year public spectacle that proved to be (with one exception) impeachment’s last hurrah in the British Isles.

This rib that the British eventually cast off was already nearly vestigial by the time we sewed it into our own Constitution in part because the British system had begun accommodating votes of confidence, making resort to impeachment unnecessary to prompt the resignation or secure the removal of ministers. It is no accident that this parliamentary mechanism makes for a broader method of housecleaning than anything available under our three-branch government. The prime minister is chosen not by the general electorate but by his fellow members of parliament and stands at the helm of a government reliant on his or her ability to command the confidence of the House of Commons. Just last September, the shattering of that confidence helped power David Cameron’s voluntary post-Brexit exit. No doubt many Americans found his resignation hard to square with our own conception of what it takes to trigger the departure of a head of government, but the difference comes down to a parliamentary government power structure exceedingly unlike our own.

Like modern votes of confidence, English history offers us limited guidance when it comes to determining the parameters for impeaching a U.S. president. As Black notes, in many of the old cases “petty acts” that “no sensible person could think impeachable offenses” served as grounds for removal. In short, our impeachment process has an obvious and important English ancestor, but for purposes of working out what constitutes an impeachable offense, we are mostly on our own. Hence Black’s decision to say little on the history of impeachment—in striking contrast with his contemporary Raoul Berger, who took a scalpel to the subject in a well-received 345-page tome the preceding year.

It is with Black’s understanding in mind that I turn to the words of Article I, section 4.

“Bribery”

The single page Black devotes to bribery amounts to a few wise words on a tricky subject that is certainly not less complicated in the presidential impeachment context than it is in a run-of-the-mill public corruption case, but neither is it necessarily more. At minimum, bribery covers not just the taking but the giving of a bribe, and state of mind is key. It is a highly fact-specific inquiry, one that requires careful examination of the “quids” and the “quos,” and most significantly, the “pro.”

The Constitution doesn’t define bribery, and for impeachment purposes, Congress could interpret the offense broadly if it so chose. But it is politically unlikely that Congress would depart dramatically from its own federal bribery statute, and presently, the public lacks the information to seriously debate whether President Trump’s conduct has triggered it.

According to Philip Bobbitt, in bribery terms, Trump "came perilously close to violating the constitution" during his private January dinner with then-FBI director James Comey when he asked if Comey wanted to keep his job and then “raised the subject of Comey terminating the Russia investigation.” But to our limited knowledge, the nexus in the Comey case is attenuated. Trump did not express to Comey his “hope” that the FBI would drop its investigation of former national security advisor Michael Flynn until two weeks after the dinner, in February. And although Comey testified that during the dinner his own impression was that Trump was “looking to get something in exchange for granting my request to stay in the job,” by Comey’s own account no such exchange was given explicit mention.

In its unanimous ruling just last year overturning former Virginia governor Bob McDonnell’s conviction on multiple public corruption charges, the Supreme Court was ultimately swayed not by “tawdry tales of Ferraris, Rolexes, and ball gowns” but by the need to tamp down on the potentially unbounded construction of federal law. In the absence of clear evidence that the president has engaged in “this for that,” Congress will be similarly wary.

“Treason”

Individuals associated with the campaign of a sitting president are suspected of colluding with a foreign government in its U.S. election interference operations. And so a specter is haunting the American presidency—the specter of treason.

Black sees no reason to say much about treason. Other than noting that it is defined in Article III in “exceedingly narrow” terms, he leaves the subject alone. In his time, there was nothing more to say; no allegations against President Nixon came within even the colloquial understanding of the word. In our own times, however, we require a bit more—but not because treason is ultimately any more legally relevant now than it was during Watergate. It’s not.

“Treason,” the only crime the Constitution explicitly defines, “shall consist only in levying War against [the United States], or in adhering to their Enemies, giving them Aid or Comfort.” The federal statute setting out the penalty for treason mirrors this language.

No one connected with the Trump campaign is suspected of “levying War.” That’s a specific offense on which Chief Justice John Marshall could not have been clearer: “There is no difficulty in affirming that there must be a war, or the crime of levying it cannot exist," he wrote for the Supreme Court in its 1807 decision in United States v. Burr. Nor is mere conspiracy to levy war sufficient; the same year, in Ex parte Bollman and Swartwout, Chief Justice Marshall stated, “However flagitious may be the crime of conspiring to subvert by force the Government of our country, such conspiracy is not treason."

As for the other half of the definition, in the absence of hostilities, Russia is not an enemy such that anyone associated with the Trump campaign can be accused of treasonously “adhering” to it. Add to that the fact that adherence is its own legal term of art, requiring “intent to betray,” as Justice Robert Jackson wrote in a 1945 decision overturning the treason conviction of a German-born American who met with two German saboteurs. Commentators have correctly noted that, contrary to Trump’s suggestion last week, even the Rosenbergs were not charged with treason for allegedly selling atomic bomb intelligence to the Soviet Union during the non-war Cold War. The now-deceased Adam Yahiye Gadahn remains the only American to be charged with treason since World War II, but we are at war with al Qaeda, to which he allegedly provided “aid and comfort” as a propagandist.

“Since the situation in our times has in no way implicated ‘treason,’ the subject may be put to one side,” Black wrote in 1974. The Kremlin’s machinations notwithstanding and even if one believes the Trump team showed disloyalty to country, this is also true today.

“other high Crimes and Misdemeanors”

Rather than dismissing outright the popular inclination to use “treason” as a framework for understanding the Trump campaign’s actual and alleged contacts with Russian officials, I think it makes sense to try to translate it. What is legally erroneous may well have a reasonable animating spirit.

You might say George Mason was moved by a similar spirit. Nine days before the Framers signed the Constitution, Mason expressed the concern that the term “treason” fails to capture all "[a]ttempts to subvert the Constitution” and pushed for the addition of a final, catch-all bucket of impeachable offenses—“other High Crimes and Misdemeanors.”

As Black recounts, during that final colloquy on September 8, 1787, Mason questioned limiting impeachable offenses to bribery and treason. Specifically citing the Hastings impeachment proceedings unfolding across the Atlantic, which had nothing to do with treason, Mason argued that the proposed draft language left “many great and dangerous offenses” on the table and proposed adding the term “maladministration” to cover the gap. James Madison, who had been among the most effective advocates for the inclusion of an impeachment provision during an early debate in July, nonetheless here objected: “So vague a term will be equivalent to a tenure during pleasure of the Senate.” At that, Mason withdrew “maladministration” and substituted the English phrase with which all of the Framers were familiar with and which gives us so much trouble today.

Black finds it highly significant that the Framers considered and rejected the term “maladministration.” The rejection suggests that certain kinds of differences, such as disagreement with the president’s policy views or handling of public administration, cannot form the bases of “high Crimes and Misdemeanors.”

Mason made a second move of great interest to Black for purposes of establishing limits on the impeachable offense: Mason noted that it was necessary to expand the grounds for “impeachment” beyond bribery and treason in light of the fact that the the Framers had decided to forbid “bills of attainder.” Under English common law, a parliamentary bill of attainder could be used to single out individual persons for guilt, “attainting” (such that they and their heirs could not own property or exercise other civil rights), and punishment without trial. Based on Mason’s unchallenged suggestion that the U.S. Constitution, in contrast, eliminated bills of attainders even with respect to the president, Black offers this insight: the phrase that the Framers ultimately settled upon, “high Crimes and Misdemeanors,” cannot be interpreted in such a way as to effectively function as a bill of attainder—or as an ex post facto law criminalizing past conduct, as that is prohibited in the same constitutional clause.

With this, elegantly, Black challenges the widely accepted wisdom that an impeachable offense is whatever Congress says it is. Not so, argues Black—at least, not for the “conscientious congressman.” Whatever presidential violation is said to rise to the level of an impeachable offense must be one “that a reasonable man might anticipate would be thought abusive and wrong, without reference to partisan politics or differences of opinion on policy.” Anything less would violate the letter or spirit of the prohibition on bills of attainder and ex post facto laws.

Having spent some time establishing what high Crimes and Misdemeanors are not, Black moves on to an “affirmative case” for what they are. He starts with a simple rule of legal interpretation: “eiusdem generis,” which translates to “of the same kind.” There is no improving upon Black’s illustration of what this rule means:

[I]f I said, “Bring me some ice cream, or some candy, or something else good,” I would think you had understood me well if you brought me a piece of good angel food cake, I would boggle a little, perhaps, if you brought me a good baked potato, and I would think you crazy or stupid or willful if you brought me a good book of sermons or a good bicycle pump.”

Black’s point is that given the structure of the impeachment provision—providing that the president shall be impeached for “Treason, Bribery, or other High Crimes and Misdemeanors”—the last category must refer to the same “kind” of offenses as “treason” and “bribery.” He interprets this to mean that the offenses must (1) be “extremely serious,” (2) “in some way corrupt or subvert the political and governmental process,” and (3) be “plainly wrong in themselves to a person of honor, or to a good citizen, regardless of words on the statute books.”

Note what Black does not include here—any suggestion that “high Crimes and Misdemeanors” must be, like treason and bribery, crimes. Instead he devotes significant energy to arguing the opposite. An impeachable offense need not be a crime—and a crime need not constitute an impeachable offense.

This first point, that "high Crimes and Misdemeanors" is not limited to indictable offenses, does not seem to be well understood by the public today, though it is the accepted view among key scholars. Raoul Berger, Cass Sunstein, Bob Barr, Michael Gerhardt, Richard Posner, and Ronald Rotunda (to name just a few) have all deployed a range of arguments to support the basic point. On this narrow issue, history alone seems to settle the matter. Pointing to key English illustrations, such as the impeachment of the Earl of Suffolk in 1386, Berger explains that that "[i]mpeachment itself was conceived because the objects of impeachment, for one reason or another, were beyond the reach of ordinary criminal redress" (p. 62). In fact, the phrase "high crimes and misdemeanors" was used in those proceedings at a time when misdemeanors were not "crimes" at all and comprised only torts and private wrongs.

Black, for his part, acknowledges the historical evidence but focuses on another tack: common sense. Using reductio ad absurdum, he offers us several “extreme examples” of behavior that is non-criminal but is so obviously outrageous as to warrant removal.

Suppose a president were to move to Saudi Arabia, so he could have four wives, and were to propose to conduct the office of the presidency by mail and wireless from there. This would not be a crime, provided his passport were in order. Is it possible that such gross and wanton neglect of duty could not be grounds for impeachment and removal?

This hypothetical, designed to be ridiculous on its face, raises real questions about the point at which neglect of duty could be grounds to remove a president. For instance, six months into the Trump presidency, the vast majority of key executive branch positions sit empty, including many created by statutes that mandate appointment for consideration and confirmation by the Senate. Most notably, the State Department is a “ghost ship,” we have been repeatedly warned. The president has publicly suggested that at least some of these vacancies are the product of his deliberate effort to eliminate "unnecessary" job posts.” Even if, as some have argued, this can in some instances amount to a failure to fulfill his constitutional obligation, the president’s behavior here is obviously not criminal. But taken to the absolute extreme—years of incompetence and a patently impotent or dysfunctional executive branch—could it constitute a basis for impeachment?

Suppose a president were to announce and follow a policy of granting full pardons, in advance of indictment or trial, to all federal agents or police who killed anybody in line of duty, in the District of Columbia, whatever the circumstances and however unnecessary the killing . . . . Could anybody doubt that such conduct would be impeachable?

Preemptively pardoning police for all killings of civilians would not be a crime and, as Black notes, could probably not be made a crime. Nor is it unequivocally unconstitutional as that term is usually understood, given the sweep of the president’s pardon power—though my own view is that it violates the president's duty to "take Care that the Laws be faithfully executed." Yet nobody could doubt that such a policy would make for a breathtaking abuse of unilateral executive authority of a kind and on a scale that plainly “corrupt[s] or subvert[s] the political and governmental process.”

This hypothetical gets at the core problem with focusing exclusively on criminal law when assessing the president’s fitness for office. The hyper-legal approach to the startling revelations flowing out of the Trump White House seems to have developed special pull under a presidency adrift, presumably because the law strikes us as an anchor that might hold us to shore in hysterical times. But there are costs to this approach to presidential conduct. If you doubt this, consider some of the cramped commentary emerging after Trump’s firing of FBI Director Comey back in May. Trump indisputably had the legal authority to fire Comey, but particularly after Trump all but admitted the firing was motivated by the desire to cool the Bureau’s Russia investigation, the decision deserved unanimous congressional disapprobation, not the mixed reception—and from some quarters, indefensible defense—that it received.

On my read, law is the North Star of impeachment discourse; it is a helpful reference point that we must always track to ensure we do not get so turned around that we stray into reactionary partisanship. Black himself fully appreciates that we “feel more comfortable when dealing with conduct clearly criminal in the ordinary sense, for as one gets further from that area it becomes progressively more difficult to be certain, as to any particular offense, that it is impeachable.” But to allow Ursa Minor to blind us to the realm of non-criminal, impeachable presidential misconduct is to misunderstand the awesome power inherent in the office—power that includes tyrant potential precisely because the alternative is to neuter the "energetic Executive" of the vitality and range of motion that Alexander Hamilton described as essential to our security and stability as a nation. Black’s extreme hypotheticals are designed to remind us that in the case of a badly behaving president, law is a lodestar, not a refuge; “the limitation of impeachable offenses to those offenses made generally criminal by statute is unwarranted—even absurd.”

Overreliance on the law is a hallmark of those who argue for impeachment, not just those who argue against it. Aware of this, Black concludes that just as all impeachable offenses are not crimes, all crimes cannot be impeachable offenses. That too, “would produce absurdities.” The datedness of one of his examples only reinforces his argument: “[S]uppose a president did not immediately report to the nearest policeman that he had discovered one of his aides was a practicing homosexual,” Black suggests, “thereby committing ‘misprision of a felony.’” The Supreme Court has since struck down anti-sodomy laws as unconstitutional, and under the relevant federal statute, one of the oldest on our books, misprision might be better interpreted to require deliberately concealing one's knowledge of a cognizable felony. But Black’s general point stands; even in 1974, he saw anything approaching this kind of alleged misprision as an unacceptable ground for forcing the president from office in permanent disgrace—no better than removing a president for obstruction of justice for “assist[ing] a young White House intern in concealing the latter’s possession of three ounces of marijuana.” As stated in the House Judiciary Committee's 1974 Staff Report on Constitutional Grounds for Presidential Impeachment, which Black elsewhere cites, "the crucial factor is not the intrinsic quality of behavior but the significance of its effect upon our constitutional system or the functioning of our government."

That’s not to say the intrinsic quality of the president’s conduct is unimportant. As Black takes care to note, common crimes like willful murder, “though not subversive of government or political order, might be so serious as to make a president simply unviable as a national leader.” This exception is not really an exception at all. Through extreme conduct that is technically personal or non-governmental in character, a president can so thoroughly establish the degradation of his own character that his continued leadership must be understood as a pox on our national polity.

Applications: “There Must Come a Point”

Black ends the chapter by running his principles through some useful mazes. At least three of his examples leap off the page in our own times: he considers the circumstances under which improper campaign tactics or obstruction of justice could constitute “high Crimes and Misdemeanors” and when the president might be held responsible for the actions of his subordinates. Each brief analysis is really a line-drawing exercise, reflecting Black’s insistence on counterbalancing certain imperfect realities—the fact that politics can be sordid, the fact that the president is only human—with the need to protect the integrity of our democratic system.

As to dirty campaign tricks, Black cautions, “I know of no offense the impeachability of which more depends on the exact case shown by evidence.” But here is how he articulates the limiting principle:

There must come a point at which the deliberate harassment of political opponents—the bugging of their offices, the circulation of known lies about them, the attributing to them of statements they never made, and so forth—takes on the character of deliberate and knowing wrong, as highly corruptive of the political process as is the actual bribery of voters. One the other hand, politics is known by all not to be croquet, and a certain amount of roughing up is expected.

The obvious present-day analogue to this Nixonian “bugging” of political opponents is Russia’s hacking of the DNC and disclosure of stolen information as part of its wide-ranging influence operations, with open encouragement from Trump and with the alleged secret knowledge or involvement of members of his campaign. But equally important is Black’s explicit disapprobation of tactics that fall short of the unlawful invasion of privacy, like extreme misattribution of statements—a harbinger of modern concerns like “fake news” and general efforts to mislead the American public. Black’s prescient move here is to spotlight how seriously we must take the clear and conscious perversion of our democratic process, irrespective of its criminality.

Black turns his practical, principled lens to the obstruction of justice. With his marijuana example, Black hints that he believes the substantiality of the foundational offense matters. Low-grade concealment or obstruction should not form the basis for impeachment where it derives from a minor offense, or no underlying offense at all. On the other hand, extreme means used to cover up even minor or purely personal conduct may mark an individual unfit for the Oval Office.

This need to consider stem and root together is an intuition that has been lost in recent discussions about whether Trump is impeachable for obstruction of justice. These discussions fully ignited in June, when fired FBI Director Comey testified that Trump privately expressed to him his “hope” that the bureau would drop its investigation into former national security adviser Michael Flynn—and this not long after Trump allegedly sought from Comey a pledge of loyalty. This falls into the category of conduct that Black likely has in mind when he writes that “obstruction of justice [that] has to do with public affairs and the political system” may be “so gross” as to demonstrate presidential unviability. But I have elsewhere disagreed with those who have already concluded, without additional facts, that Trump’s alleged coaxing would make for impeachable obstruction. There are few things graver than presidential interference with the Justice Department’s independence, but at this juncture there is no denying that the perceived legitimacy of impeaching Trump for obstruction of the FBI’s Russia investigation may turn, at least in substantial part, on whether that underlying investigation reveals he and his team committed any serious wrongdoing on the collusion front.

Black’s distaste for absolutism on matters of obstruction comes across most clearly when he suggests mercy may be warranted for the president who acts improperly on behalf of others, rather than himself. “I would have to say that the protection of their own people is in all leaders, up to a point, a forgivable sin,” says Black. And yet “when it occurs in connection with governmental matters, and when its perpetrator is the person principally charged with taking care that the laws be faithfully execute, there must come a point at which excuses fail.” Again, “there must come a point.” We must be willing to identify—and it is inevitably a fact-intensive task—where the current changes and we are in dangerous waters; again, in light of the power and trust vested in the president, that place need not be found in a criminal statute.

Handily, here Black shifts from obstruction of justice to an assessment of when the president must bear accountability for his subordinates’ misdeeds, a subject of clear relevance today. The ongoing congressional and FBI Russia investigations have, from the beginning, centered on the alleged contacts between Trump’s campaign associates and Russian officials, and this has naturally given rise to questions about Trump’s awareness and involvement. Speculation about what the president knew and when has congealed around Trump’s long-running commitment to protecting Flynn, his embattled former national security adviser, and has only mounted in the wake of the latest news that his son Donald Trump, Jr., met with the Kremlin-connected Russian lawyer Natalia Veselnitskaya in June 2016 for the express purpose of reviewing potentially damaging information about then-presidential candidate Hillary Clinton. As the American public digests this information, it is worth remembering that no president can or should be held responsible for the wrongs of all persons working under him. Black advocates for a sensible approach that turns on careful consideration of the extent of the president’s knowledge and moral culpability.

On the other hand, “the president (like anybody else) is totally responsible for what he commands, suggests or ratifies.” Here it is possible, I think, to agree with Black’s general point without agreeing with his parenthetical. While Black is surely correct to assert that the president must be held responsible for his suggestions, it seems worth noting that this is particularly true of the president, who on account of his frankly enormous power is not quite “like anybody else.” We can accept Richard Neustadt's insight that presidential power is “the power to persuade" and that not all presidents wield anywhere near the same wattage—and still insist that our commander-in-chief be assumed to speak with the expectation that his subordinates will take him seriously.

The upshot is this: that a president has merely suggested and not ordered gross misconduct of a subordinate should be a distinction without a difference for purposes of ascertaining presidential intent or culpability.

And yet the notion that there is a difference came to the fore last month during a public hearing before the Senate Intelligence Committee, when Director of National Intelligence Dan Coats and National Security Agency Director Adm. Mike Rogers declined to address whether the president had ever asked them to tamp down on the Russia investigation, as the press had previously reported. Instead, they reiterated that they had never been so "directed" or made to feel “pressure.” Their refusal to offer an unqualified denial that Trump had made any inappropriate requests understandably raised concern among some members of the Committee.

There are different ways to downplay how much the president’s words matter—subtly, by making much of the distinction between suggestions and instructions, or audaciously, by asserting that the man knows not what he is saying. Whatever the method, the result is an inversion of the executive responsibility chain. Consider, for example, Attorney General Jeff Sessions’s June testimony before the Senate Intelligence Committee. When Senator Marco Rubio (R-Fla.) asked whether concerns about propriety caused Sessions to linger before leaving Comey and Trump to their private February 14 meeting in the Oval Office, Sessions replied that the meeting “didn't seem to be a major problem.” Why not? “I knew that Director Comey, long-time experienced individual of the Department of Justice, could handle himself well.”

Sessions’s statement may well reflect the practical reality: more often than not, the difference-maker in assessing the significance of a president’s improper suggestion or command could be whether his subordinates choose to cooperate. Where they do, the president’s nudge is as good as an order. Where they don’t—and Coats, Rogers and Comey made clear they never would—it may be difficult to hold the president to account for what has, after all, amounted to an ineffectual tug.

Yet Sessions’s answer, offered in response to an inquiry about the president’s alleged attempts to influence the FBI’s Russia investigation, should trouble us. Implicit in it is the suggestion that little harm can come of the president’s conduct so long as those around him do not bend. Once we accept that, Black’s buoy line is sunk. Surely we can agree a president’s willingness to try his hand at improper influence, however unsuccessful, should in some cases render him unsuited to the office. The general idea, one that Black repeats, is the resounding theme of the chapter and the forest that must not be missed for any tree: “There must come a point.”

For those not inclined to delve too deeply into the nature of the impeachable offense at a time when the ice caps are melting, Black cuts to the chase in the space of two paragraphs, each neatly summing up the Blackian perspective on what lies on either side of the impeachability line:

Omitting qualifications, and recognizing that the definition is only an approximation, I think we can say that “high Crimes and Misdemeanors,” in the constitutional sense, ought to be held to be those offenses which are rather obviously wrong, whether or not “criminal,” and which so seriously threaten the order of political society as to make petulant and dangerous the continuance in power of their perpetrator. The fact that such an act is also criminal helps, even if it is not essential, because a general societal view of wrongness, and sometimes of seriousness, is, in such a case, publicly and authoritatively recorded. The phrase “high Crimes and Misdemeanors” carries another connotation—that of distinctness of offense. It seems that a charge of high crime or high misdemeanor ought to be a charge of a definite act or acts, each of which in itself satisfies the above requirements. General lowness and shabbiness ought not to be enough. The people take some chances when they elect a man to the presidency, and I think this is one of them.

The Procedures

As America was reminded in 1868 (with the acquittal of President Andrew Johnson) and again in 1999 (with the acquittal of President Bill Clinton), impeachment is a only the first half of a two-part process. The House of Representatives has the “sole Power of Impeachment,” which means only it, by simple majority vote, may charge the president with the commission of impeachable offenses by passing one or more Articles of Impeachment. The Senate then tries the impeachment, with the Chief Justice of the Supreme Court presiding and “managers” appointed by the House presenting the case for removal. After hearing the evidence, the Senate votes on each individual Article much the way a trial jury would vote on each count of a criminal indictment, and a two-thirds majority is required to convict the president on any charge.

The distinctness of these roles requires that each chamber act with great care. The House must draft Articles that clearly and comprehensively cover those offenses that can form the basis for successful conviction—theoretically what the Senate uncovers in the way of evidence could make for a new impeachment in the House, but this volleying back and forth is, as Black points out, politically unlikely. As for the Senate, at the tribunal stage each senator functions both as a juror making findings of fact and a judge making findings of law. This is important. Recall that during Clinton's impeachment proceedings Senator Tom Harkin went so far as to object, successfully, to the House managers' repeated references to the senators as "jurors" on the ground that this ignores their equally important role as “judges” charged with construing law.

In other words, the broad question that the Senate is tasked with answering—whether the president has committed an impeachable offense—really breaks down into two different questions. The fairly staid question of fact: “Did the president do what is alleged in this Article with having done?” The more dramatic question of law: “If he did, did that action constitute an impeachable offense within the meaning of the constitutional phrase?”

That the the difficulty of these questions is not widely appreciated may have something to do with the framing mistake that poisons so much of our impeachment discourse. Already pollsters are asking Americans whether they support impeaching Trump, as though the months-long investigation that goes into an actual impeachment inquiry—usually conducted by the House Judiciary Committee to determine whether impeachment is warranted upon referral by the full House—is a mere formality. Black saw periodic public opinion polls on presidential guilt or innocence as an “unspeakable indecency” that might well pervert the results of the Senate trial; it seems safe to say he would also disapprove of such polls conducted prior to the initiation of even preliminary proceedings in the House. That’s not to say these early polls might not serve some function; at the extreme, they may well translate public unrest into a language that Congress, however inertial, cannot ignore. But it is a mistake to rely on them as indicative of presidential removability.

More broadly speaking, however hard the press works, the conflicting, limited and second-hand nature of the evidence to which the public has access almost always makes it inappropriate to ask, before proceedings have even started, whether the president should be impeached. The question is whether an impeachment inquiry is in order.

When a presidential candidate openly encourages a foreign government to interfere with our election, fires the FBI director once in office, and then indicates on national television that the firing was motivated by the director’s role in leading an investigation into possible contacts between the foreign government and the president’s campaign associates, an argument can be made that an impeachment inquiry is, indeed, in order. And for Congress to refuse to at least soberly entertain the possibility under these circumstances is to forsake its own constitutional obligations.

The facts do not yet support an impeachment. Neither do they support the refusal to think about the option and the circumstances that could demand it. All members of Congress, oath-bound to support our Constitution, could—indeed, must—hold these two ideas in their minds at the same time.

Criminal Law Analogues

As Black explains, when it comes to some of the nittier procedural details, the challenge lies in determining which parts of the impeachment and trial process should be treated like their criminal law analogues, and which parts need not be. He starts with some technical examples: What should be the burden of proof, and what are the rules for the admissibility of evidence? He concludes that on both questions, logic dictates some departures from criminal law.

Take burdens of proof. In criminal cases, the jury must be convinced “beyond a reasonable doubt” on every fact required to establish guilt for the offense charged. The courts have generally declined to translate this standard into numerical terms, but that hasn't stopped judges and scholars from attempting to quantify it: popular proposals range from an 80 percent chance of guilt to 99 percent. The point is that the standard requires a high level of certainty—in contrast with civil cases, where the verdict goes to whichever side supported by a “preponderance of the evidence”: 51 percent. Black reasons that the proper standard for finding the president guilty of an offense probably falls somewhere between the civil and criminal poles.

As for the admission of evidence, Black makes what I think amounts to a conclusive argument that the technical rules of evidence “have no place in the impeachment process.” The House and Senate should review all relevant evidence, full stop. After all, there is no way to keep “hearsay” from Congress, the way it is kept from sequestered juries. When it comes to circumstances and facts that suggest the unreliability of certain evidence, it is on the House and Senate to exercise their judgment to “appropriately discount[]” that evidence.

Executive Privilege

Six months into the Trump presidency, executive privilege has already become a subject of great general interest. Last month, citing “longstanding Department of Justice practice,” Attorney General Jeff Sessions drew fire for repeatedly declining to provide the Senate Intelligence Committee details about his personal conversations with the president about Comey’s firing or the Russia investigation. Democratic senators reacted with great consternation, pointing out that Trump had not actually invoked executive privilege.

But it is hardly unusual for an administrative official—particularly one appearing voluntarily rather than by way of subpoena before a congressional committee—to decline to speak on matters discussed with the president until and unless the president has issued an affirmative decision on the matter. And it seems certain that Black would be sympathetic to Sessions’s decision to err on the side of keeping Trump’s confidence until such time.

Black's book went to print shortly before the Supreme Court unanimously ruled that President Nixon must comply with a subpoena for presidential recordings and papers obtained by the special prosecutor investigating the Watergate break-in. Though Black favors an expansive interpretation of the scope of executive privilege, despite knowing it to be unpopular, for the most part the Court’s decision does not counter Black’s views.

As a threshold matter, that case has limited application for impeachment purposes because, as Black notes, the question of whether Congress can compel information from the president or his associates during impeachment proceedings is separate and apart from the question of whether the courts or congressional committee operating in the normal course may do so. Second, Black observes that the privilege would seem to make for a stronger claim earlier in the proceedings, when the inquiry is not yet focused, and a weaker claim when issues have narrowed and proof of specific facts is sought. Third, iterating a point that the Nixon Court similarly emphasizes, Black recognizes that presidential confidentiality may be claimed for “two quite different reasons”: because its substantive content must be protected for national security reasons, or because regardless of the sensitivity of the information, disclosure of White House conversations will necessarily impede the president’s ability to freely consult with his advisors and others without fear that those tentative deliberations might be compelled from them at the drop of a congressional committee’s hat. Even if the latter fails in the face of a “demonstrated, specific need for evidence”—as the Supreme Court decided it did in the criminal law context presented in Nixon—the Court echoed Black’s insistence that confidentiality in the name of national security receive greater deference.

An interesting corollary that comes of this last point is the near-impossibility of seeking to impeach the president for certain kinds of abuses, at least in the absence of visible, tangible blowback to U.S. interests. For example, Black points out that if the president were charged with “dangerously denud[ing] the United States of its defenses,” it could be that the president has a “plain duty” to decline to furnish Congress with information it might need to delve into this charge, such as closely-held military secrets. This doubles as an explanation for why even if Trump furnished Russian government officials with highly classified information from Israel during his closed-door May 10 meeting for no reason other than a fit of braggadocio, as the New York Times reported, such an event has little potential as a stand-alone basis for impeachment. Such a charge regarding conduct or information so firmly within the president’s purview would be difficult to even investigate, much less prove.

Public Hearings

Some of Black's observations about public access to impeachment and trial proceedings have stood the test of time. For instance, he suggests that early in the investigation, confidentiality and the need to prevent public disclosure of evidence not yet vetted for its credibility or relevance might necessitate closed-door proceedings.

In our media-soaked times we are less likely to accept Black’s argument that though the Senate trial should be public, “radio, television, and cameras” have no place in it. I think as a categorical rule, his argument must be rejected, as it amounts to giving the Washington establishment a front-row seat to proceedings of historical importance that the rest of the country is relegated to experiencing only second-hand. But the general concerns underlying his view are valid, and the Senate should consider them when calibrating how much of the proceedings are to be televised: Black worried that the injection of media would be unnecessarily humiliating, threatened to change the character of the proceeding, and could create “public pressure for some given result” (p. 20). These points are worthy of greater consideration than they received in 1998 when, two weeks before the House Judiciary Committee began its formal impeachment inquiry, the House voted to release the recording of Clinton’s four-hour, closed-door testimony before a grand jury in connection with the Paula Jones sexual harassment case.

Impeachment and the Courts

The Senate’s conviction or acquittal of the president—or any civil officer subject to impeachment proceedings—is not subject to judicial review. Nowhere does the Constitution explicitly state this, but by now it is a point beyond question.

To drive home how nonsensical the alternative would be, Black asks us to follow it out to its logical end. Imagine that a majority of the House has impeached and a supermajority of the Senate has convicted the president. Now imagine the president refuses to leave the Oval Office and appeals to the Supreme Court, which splits 5-4 on some issue, like the definition of “high Crimes and Misdemeanors.”

“So it puts the impeached and convicted president back in for the rest of the term. And we all live happily ever after.”

This is “preposterous” by Black’s lights. To reinstate a president already stripped of all legitimacy is to dress a puppet. This is the major point. Lesser reasons include the text and logic of the Constitution, which deliberately moves impeachment into the House and Senate and not the Supreme Court. Some twenty years after the publication of Black's book, the Supreme Court agreed with Black, and then some, in a unanimous decision declaring that authority over impeachment trials “is reposed in the Senate and nowhere else.” That means the courts are barred not only from reviewing the results of an impeachment trial, but also from dictating the Senate’s tribunal procedures (including the Senate’s sometimes-practice of delegating the hearing of evidence to a special committee, which Black thought unconstitutional—but which he also thought highly unlikely to be employed in trying a president).

The rest of Black’s argument against judicial review is more technical than anything I need to note here, given it is the least controversial of all possible points in the otherwise fraught realm of impeachments. The more interesting question is whether the courts can assist in impeachment investigations—say, by ordering the jailing of a recalcitrant witness who won’t provide testimony or documents, to borrow Black’s example. Black concludes there are no constitutional grounds for objecting to this, though there are some practical reasons Congress might want to avoid enlisting the courts’ help. Congress “loses control of its own business when it brings that business into court,” since Congress cannot dictate the outcome of court proceedings. Should a court decide a witness jailed for contempt was privileged not to testify, there is nothing the Senate can then do to assert otherwise.

Each chamber has “considerable inherent power to punish for contempt, without recourse to the courts,” and we can expect both the House and Senate to wield it.

Short of Impeachment

In April, Allan Lichtman, the history professor at American University who predicted Donald Trump’s win, released a book that sets out the case for impeaching Trump. Such a project is fundamentally different from Black’s. The purpose of Black’s book, published when the country was much further down the impeachment pipeline, was not to argue for Nixon’s removal (“. . . I do not intend in any way to judge any real-life issue.”) but to provide citizens a simple framework for how to navigate a subject of crucial public import wrapped, by convention, in noise.

Lichtman rightly points to myriad problems that plagued the presidency from the moment Trump stepped into office. Those who downplay these features—particularly Trump’s open collusion with the Russian government on the matter of his opponent’s stolen emails and his unprecedented use of the presidential office for apparent personal profit—as wholly unimportant, or immune from scrutiny when assessing Trump’s fitness on account of the electorate’s decision to Trump into office despite them, do the country a great disservice. They also disregard the purpose of impeachment as a stopgap designed to protect the country from, in the words of James Madison, the “incapacity, negligence or perfidy of the chief Magistrate.”

On the other hand, it is clear to me that we do not yet have unequivocal evidence Trump has done anything “impeachable.” By this, I mean to emphasize not what Trump hasn’t done, but what Congress hasn’t done.

As Black points out, in this book and elsewhere, our system has many means short of impeachment when it comes to checking and even punishing executive overreach. And yet when dissatisfied with the president or the presidency, we tend to think in black and white, live or die; in Black’s colorful phrasing, when confronted with a misbehaving president, we “reach for the spear of impeachment” as though we are a single-sanction system and have no recourse but his elimination.

This is far from true. Congress need not “sit idly by, counting up grievances, until time comes to call a council of elders and sharpen the impeachment spear.” Extending his logic a bit, particularly given his early argument that to impeach the president for an action that Congress dawdles in forbidding makes for “sailing very close to the wind,” I think Black is also making the more striking assertion that the parameters of an impeachable offense are necessarily affected by Congress’s failure to exercise its power to prevent or respond to the offense, where it could effectively do so.

This is the central difficulty with claiming that Trump’s refusal to divest from his massive business empire is by itself an impeachable offense. The assertion seems at odds with the House of Representatives’ refusal to so much as demand the disclosure of Trump’s tax returns. That’s not to say that Trump cannot be impeached for specific improper actions taken to the clear detriment of U.S. interests in connection with his business empire if such actions later come to light. I am merely explaining that Congress’s cowardice and refusal to act in curbing the president does not simply undercut its ability to cry foul when he goes too far; this failure actually shifts the line demarcating “too far”—or erases it altogether.

Black offers an important example of exactly this sort of congressionally-created disaster early in his book when describing whether and when unauthorized military action can constitute an impeachable offense. “This I find the most agonizing question of all.” One would think, says Black, that unwarranted and unauthorized instigation of hostilities by the president is the “grossest usurpation of power, clearly impeachable.” But there are immense practical difficulties with identifying or calling the president to account for such usurpation.

My view is that the president is unlikely to engage in hostilities without putting forth some national security justification, however novel, and congressional torpor in responding serves as a kind of assent that insulates the president from charges of abuse and certainly from any impeachment rumblings. Back in April, when Trump launched almost 60 cruise missiles at a Syrian airfield in response to Syrian President Bashar al-Assad’s use of sarin gas against how own civilians, Trump seemed to justify the strikes based on the U.S. interest in maintaining regional stability and preventing the use of chemical weapons. Jack Goldsmith has explained that this was a marked expansion of the criteria for what makes for national interest warranting unilateral executive action, while Harold Koh has argued that in some circumstances, without congressional sign-off, the president may use limited force "to prevent a genuine humanitarian disaster.” But whatever the argument, this much is clear: Congress’s failure to assert its authority on the matter after the fact makes it inconceivable that Trump’s action, politically very popular in some quarters, could be raised as a basis for later impeachment.

As Black says, in many cases, if Congress chooses to draw clear lines, “then the president’s violation of the congressional rules would be impeachable beyond a doubt.” But there is a flipside to this coin. Particularly when the president acts purportedly to further U.S. national security interests, Congress’s decision to not respond seals off the president from an impeachment inquiry.

By Black’s diagnosis, “Congress must share the responsibility for the twentieth-century aggrandizement of the presidency.” And so, with devastating clarity, Black ends the way he begins: by reiterating the graveness of impeachment as a constitutional weapon—so grave that its sudden deployment after an established pattern of congressional acquiescence must be interpreted as its own kind of lawlessness. Removal of the president of the United States cannot be conceived as hitting the switch and eliminating the energy source that we think has grown to threat proportions. And any congressional inclination to do so must be judged severely in those cases where Congress is itself complicit in enabling executive abuse, be it committed in the name of the public interest or in the naked pursuit of personal profit.

Possibly Congress would do less ducking if it embraced in general what is true of impeachment in particular. Punishment is not the chief point, Black points out—the Constitution makes this clear by specifically providing that any impeached person may be held to account in separate criminal proceedings after his conviction in the Senate. Impeachment is primarily about protecting the national interest going forward: When we remove the president, we do so “principally because we fear he will do it again, or because a traitor or the taker of a bribe is not thinkable as a national leader."

This is why to resist impeachment and its attendant process to the end, even when the president has proven himself unfit for the office or even malignant to the collective welfare, is no less a partisan dereliction of duty than unduly clamoring for his removal. As Arthur Goldberg, the retired Supreme Court justice, observed shortly after the House Judiciary Committee began formally investigating whether there were grounds to impeach Nixon, the Framers understood how disruptive impeachment proceedings could be but also “that it would be more dangerous for the country to have no remedy against betrayal of the public trust.”

It is on Congress to identify when that remedy is needed, and on Congress to administer it with “faultless lawfulness.” To fail on either score is to taint the cure. To succeed is only to begin the hard work of rehabilitating the presidency and restoring public faith in our elected representatives’ ability to honorably navigate the thick skein of choices that hold together our system of government.