President Donald Trump has been accused of committing innumerable “high Crimes and Misdemeanors.” When we released To End A Presidency: The Power of Impeachment in May 2018, we took pains to separate the wheat from the chaff. We concluded that four alleged impeachable offenses merited further investigation: (1) improper dealings with Russia surrounding the 2016 presidential election; (2) obstruction of justice in Russia-related investigations; (3) abuse of the pardon power; and (4) implementing kleptocracy.

We stand by our original conclusions. Indeed, in many respects the facts bearing on these four issues have grown worse for Trump. The evidence of sketchy interactions with Russia during the election is now much stronger; his assaults on the Russia investigation have continued apace; and Trump’s financial entanglements with hostile powers have cast a pall of corruption over key foreign policy judgments.

Recently, House Speaker Nancy Pelosi threw cold water on calls for immediate removal proceedings. “Impeachment,” she warned, “is so divisive to the country that unless there’s something so compelling and overwhelming and bipartisan, I don’t think we should go down that path, because it divides the country.” This is a wise political and constitutional judgment—for now. Given what is currently known, and given the state of the nation, we need investigation, oversight, and deliberation, not a rush toward impeachment.

In conducting investigations, though, Congress isn’t required to ignore the possibility that Trump might have committed impeachable offenses. To the contrary, Congress has a moral and political duty to investigate any potential “high Crimes and Misdemeanors.” In addition to the four listed above, we would flag two more subjects of investigation. We think it’s essential to probe both topics, but we also believe that they each involve a number of under-appreciated complexities that merit further examination.

In light of events since May 2018, we now believe that two more potential “high Crimes and Misdemeanors” warrant investigation. But we also believe that both of them involve a number of under-appreciated complexities that require further reflection.

The first such offense is corrupt failure to defend the United States—and its electoral system—against domestic operations launched by a hostile foreign power. As Bob Bauer has written on Lawfare, “Trump is misleading the American people about the very fact of Russia’s actions and, according to intelligence officials, Russia’s plans to press [its] attacks in the future. He has declined to vigorously lead in defending against these assaults: He is virtually flaunting his unwillingness to do so.”

One of the president’s most basic responsibilities is to protect this nation from foreign attacks. Just as he is obliged to repel foreign armies, so must he guard against cyberattacks and intelligence operations designed to destabilize democracy and undermine our electoral system. In light of the overwhelming, terrifying evidence of ongoing Russian interference, Trump’s ostentatious failure to defend the country—or even to recognize that we’re under assault—is an unconscionable abdication of his duties as president.

It is possible to argue that Trump’s inaction is, by itself, an impeachable offense. On this view, Trump is guilty of nonfeasance: a failure to act when action is required. Yale Law Professor Akhil Amar has written that “gross dereliction of duty imperiling the national security… might well rise to the level of disqualifying misconduct.” Or to offer a closer analogy, imagine if Franklin D. Roosevelt had done nothing on December 7, 1941; it seems hard to imagine that he wouldn’t have been removed for inaction (and rightly so). Several commentators, including Elizbeth Holtzman, have relied on similar logic to contend that Trump’s failure to act in response to Russian attacks on our democracy is inherently impeachable.

Of course, as philosophers delight in pointing out, the line between “action” and “inaction” is slippery. That is most certainly true here.

It appears as though Trump has not merely forgotten or neglected to act; rather, he has made a considered decision against doing so. Put differently, his chosen course of action is not to act. Viewed this way, the key question is why he has decided against defending the nation. Does he have a comprehensible, legitimate justification relating to foreign policy, domestic governance, or America’s national security? In that case, his only offense may be maladministration. Or are his motives largely or entirely illegitimate?

In our view, it would be appropriate to impeach a president who ignores a nation’s attacks on our democracy because he hopes that nation will help him (or his political party) at the polls or in future business endeavors; or because he fears compromising the legitimacy of his own election; or because that nation has some kind of actual or suspected leverage over him or his family. Trump’s motives for adopting this policy of apparent inaction are therefore worthy of investigation.

Any such investigation should also encompass the other elements of “high Crimes and Misdemeanors.” Many nations engage in intelligence and cyber operations directed at the United States. The president is not mandated to address every single one. Impeachment would be permissible only if Trump’s failure to act in response to Russian inference was, in fact, likely to pose a grave risk of harm to the nation. Congress would also have to assess whether Trump’s failure to act was so clearly wrong that he had fair notice of potential removal on this basis. To make these determinations, Congress would have to weigh Trump’s motives for inaction, which might themselves signal a substantial risk of harm to the United States. Further, Congress would likely need to assess intelligence findings, prior counterintelligence activities, our relationship with Russia, and the state of global affairs.

The complexity of these judgments might make it difficult to justify impeaching on this basis. But we believe that Trump’s failure to defend the nation may, in principle, qualify as impeachable.

The same is true of allegations that Trump broke the law during the 2016 presidential election. Here we have in mind Trump’s personal involvement in directing payments to two women to suppress their allegations of sexual impropriety. Trump appears to have given this order not to protect his family or private reputation, but to benefit his campaign.

That conduct, undertaken in concert with his lawyer Michael Cohen, violated federal law and deprived the public of facts that Trump evidently feared might turn voters against him. Here’s how prosecutors described the nature and gravity of the offense in a sentencing memorandum for Cohen: “While many Americans who desired a particular outcome to the election knocked on doors, toiled at phone banks or found any number of other legal ways to make their voices heard, Cohen sought to influence the election from the shadows. He did so by orchestrating secret and illegal payments to silence two women who otherwise would have made public their alleged extramarital affairs with Individual-1 [a.k.a. Trump]. In the process, Cohen deceived the voting public by hiding alleged facts that he believed would have had a substantial effect on the election.”

The Manhattan-based prosecutors who filed this memo are independent of Special Prosecutor Robert Mueller. And they found that Cohen “acted in coordination with and at the direction of Individual-1.”

Trump and his lawyers have desperately downplayed the seriousness of this allegation. They have also pretended that the campaign finance laws are confusing, or ambiguous, on the legality of this conduct. Poppycock. It seems fairly clear that the president personally directed criminal conduct for the specific purpose of increasing his odds of winning the election. As election law expert Professor Rick Hasen has observed, “These are serious criminal activities for which others have gone to jail.”

The main question that remains is whether Trump willfully broke the law when he directed Cohen’s conduct. But given the nature, timing, and elaborate structuring of these hush payments, as well as Trump’s participation in the meeting where the scheme was set up, it seems likely that the president willfully directed a crime in hopes of affecting the election outcome. This assessment of Trump’s mental state is bolstered by his subsequent conduct: shifting from one lie to another as evidence came to light proving that he knew about the payments and helped orchestrate them. That isn’t how an innocent man behaves.

Viewing Trump’s conduct as a whole, we see a sustained disregard for the law—and a willingness to use his wealth in illegal ways while buying silence from those who might harm his political fortunes with the truth.

As we detail in To End A Presidency, pre-inauguration wrongdoing aimed at the corrupt acquisition of office is impeachable. So Trump’s misconduct can’t be set aside on the ground that it occurred before Election Day. This raises a question: how do we decide when pre-inauguration conduct is properly ranked as a “high Crime and Misdemeanor”?

Yale Law Professor Philip Bobbitt has recently identified several principles to guide this analysis: “When a substantial attempt is made by a candidate to procure the presidency by corrupt means, we may presume that he at least thought this would make a difference in the outcome, and thus we should resolve any doubts as to the effects of his efforts against him. Yet we must confine the operation of such a rule to truly substantial [misconduct], lest we ensnare every successful campaign in an unending postmortem in search of [impeachable] misdeeds.” As Bobbitt’s formulation suggests, not every campaign misdeed—indeed, not every crime—will qualify as an impeachable offense.

“ What does seem clear is that Trump engaged in meaningful election-related misconduct. ”

In that analysis, it may be relevant whether the candidate’s misdeeds actually affected the election outcome. But in our view, that is not (and can’t be) the determinative question. Campaigns are chaotic, contingent, and highly momentum-driven. Their outcomes invariably have many causes. Except where a candidate tampered with ballots or bribed members of the Electoral College, it will nearly always be impossible to assess in retrospect whether a specific misdeed affected the outcome. That is especially true when the misdeed involved stealing information or silencing accusers.

As Bobbitt suggests, the more helpful question is whether a candidate believed his conduct would likely affect the outcome. We might also focus on factors including the scope and severity of the offense, whether it was linked to a broader pattern of misconduct, whether it is likely to recur in future political efforts, whether it may compromise the candidate once in office, and whether it involved creating and coordinating a multi-member criminal conspiracy.

We are not yet in a position to answer some of these questions with respect to Trump’s hush money payments. What does seem clear is that Trump engaged in meaningful election-related misconduct—some of which involved contact with foreign powers, some of which involved violations of federal criminal law, and some of which might check both boxes. It is also clear that numerous senior figures around Trump, not to mention Trump himself, have lied about important facts relating to his campaign activities while seeking to discredit investigators.

Congress and federal prosecutors should therefore persist in their efforts to ascertain what happened. Congress must then decide how to respond to any evidence of presidential wrongdoing, speaking for the nation as a whole.

Excerpted and adapted from To End a Presidency: The Power of Impeachment by Laurence Tribe and Joshua Matz and published by Basic Books