The argument against the indictment of the president rests on a 2000 Office of Legal Counsel (OLC) opinion , affirming the office’s conclusion 27 years before. In reliance on these opinions, members of the “no indictment” school take one of two positions—or sometimes both. One view holds that, whatever the merits of the opinion, Special Counsel Robert Mueller is bound by law to follow it. The other embraces the opinion’s reasoning and holds that the OLC’s reasoning is both binding and correct.

There is good reason to question the soundness of OLC’s conclusion, and Andrew Crespo has argued impressively that, as special counsel, Mueller may be free to disregard it. But also significant in evaluating the OLC’s conclusion is the answer to this question: Would Mueller’s investigation, if it cannot produce indictment of the president while in office, otherwise inform lawful remedies for presidential misconduct? It is assumed so, but it seems that both theoretical and practical problems with this view are routinely overlooked.

No one argues that Mueller investigation, if it uncovers evidence of criminal conduct should have no consequence for the president. Defenders of the OLC position argue that the special counsel may, should and doubtlessly will produce evidence that Congress may use to consider impeachment. This is the point on which OLC landed in 2000, arguing that even if the president cannot be indicted, the "constitutionally specified impeachment process ensures that the immunity will not place the president ‘above the law’." While the special counsel or prosecutor cannot indict on his evidence, his case just moves to the Congress.

In presenting this answer, proponents are confident that the case the special counsel assembles will find its way to the legislature, by action of the Attorney General, who receives a report from the special counsel and reports in turn to the Congress. The House and Senate would then take up impeachment on the case Mueller has developed.

This is deemed the constitutional route to a remedy when indictment is not an option. The president’s stability and capacity to function, so central to the OLC analysis, would be thereby preserved. Yet, at the same time, the president does not go scot-free. Congress judges his conduct, informed by the special counsel’s work.

This line of argument exposes a major problem with the no-indictment posture. It presumes that it offers a “clean” balancing of institutional equities and resolution of separation of powers issues. But it is not so clean. Somewhat imperceptibly, it shifts the judgment of the president’s conduct to the untenable ground on which the confrontation between President Bill Clinton and Independent Counsel Kenneth Starr took place. Congress would largely decline responsibility for its own independent fact-finding. It would rely instead on what the prosecutor found, perhaps calling some witnesses and holding hearings to reinforce the narrative his investigators built. The president’s defense would be a rebuttal of the special counsel.

One feature of this awkward institutional arrangement is that the executive becomes the investigative agent for the Congress. The special counsel may not indict, but he may investigate, and his inquiry as it affects the president establishes the record on which Congress relies in considering impeachment. As a subordinate of the president within the executive branch, he is put in the position of aiding the legislature in the task of considering whether to remove his superior. It is hard to see how this is the solution that those opposing indictment urge as the only one to protect the “unitary executive.”

Evaluating or making the case for impeachment is not a mere byproduct of the special counsel’s work under this conception of his role. This would be his job. He would understand that, not able to indict the president, he is obliged to put Congress on notice of evidence of serious wrongdoing. It is certainly the expectation he would see expressed in elite and public commentary. He will then inevitably consider whether the evidence is not only sufficient to support indictment, a course not open to him, but also to warrant consideration of impeachment. The standards are not the same. Indictable obstruction is not necessarily the same as impeachable obstruction. A case like that of former Governor Bob McDonnell of Virginia brings out the point that a politician may face investigation for behavior that disqualifies him for office but need not land him in prison.

In assessing his case, and in the eventual report to the attorney general, the special counsel cannot escape this pressure to distinguish clearly between the indictable and the impeachable—or not. The counsel may then be drawn into making an anticipatory judgment about impeachment that is reserved for Congress. Perhaps for that reason, the special counsel regulations departed from the defunct independent counsel law in omitting provision for referrals to Congress of evidence of impeachable conduct. As explained in the course of the rulemaking, the special counsel regulations call only for a “limited” report from the special counsel to the attorney general.

In turn, the attorney general reports to Congress and, subject to grand jury and other protective rules and policies, decides on the public release of the report if in the public interest. But the scope of the public interest the attorney general may consider is defined narrowly as “congressional and public confidence in the integrity of [the special counsel] process.” Nothing in this language or the stated rationale for the rule suggests it contemplates—and it certainly does not require—notification to Congress of impeachable conduct

One might think that in crafting the rules this way, the Justice Department was simply feathering its executive nest. But some commentators, apparently affected by the Clinton-Starr experience, agreed that it was best not to direct department to involve itself directly in impeachment matters. A Brookings-American Enterprise Institute Task Force, chaired by former Senate leaders George Mitchell and Bob Dole and whose members included now Chief Justice John Roberts, specifically recommended that the special counsel regulations leave out reports of potentially impeachable offenses. It concluded that it was preferable to leave Congress to seek information as needed from the executive branch. Congress had to be the prime mover.

Out all of this arises a clear complication. It is not certain that the department will or must share a prosecutor’s investigative product and conclusions with Congress in aid of a potential impeachment inquiry. That very investigation, however, may be the focus of the questions of impeachment. Congress, and probably a large share of the public, will believe that it is entitled to this work. In fact, many members will believe that the strength of the prosecutor’s criminal case should determine the strength of the case for impeachment.

So it turns out that the Justice Department’s obligations are not so clear after all. A “worst of all worlds”—or, at least, a badly muddled situation— may materialize. Under the OLC opinion, the special counsel faces a proscription on acting in the ordinary course, that is, prosecuting if the evidence supports the charge, but the regulations under which he operates raise a question of the support he may extend in the alternative to the congressional impeachment process.

The 2000 OLC opinion assumed away the problem. The immediate past history of the impeachment process might have led the office to take for granted the prosecutor’s active engagement with the Congress. OLC was most of all worried to block off the dangers flowing out of a president’s vulnerability to indictment. A principal concern was giving a prosecutor (and his grand and trial juries) untenable power over a president’s continuance in office: This, OLC suggested, "would place in the hands of a single prosecutor and grand jury the political power to interfere with the ability of a popularly elected president to carry out his constitutional functions."

The Clinton-Starr case shows how this all comes around to the same thing if the prosecutor becomes the Congress’ vehicle for shaping the case for impeachment.

The House of Representatives in the Clinton case deferred entirely to Independent Counsel Ken Starr. It impeached the president without deposing a single witness. It did, however, take testimony from Starr, and the defense trained its fire on him from beginning to end. The Senate did depose witnesses—three in all.

From the beginning to end, the impeachment turned on Starr. In presenting the case against impeachment, Minority Counsel Abbe Lowell took aim at Starr:

As this committee has chosen to receive Mr. Starr's referral and its conclusions and the material he decided to send in determining whether there is clear and convincing evidence to support impeachment, and as we claim -- indeed, I think as the minority staff has proven -- that such large gaps exist in the evidence, it was essential on Nov. 19, as it is now, to determine whether his material can be trusted, whether it is accurate, whether it is complete and whether it is biased …

Majority Counsel David Schippers was not wrong to suggest that, summed up, the Democratic defense of the president was that “Judge Starr is a prosecutor most foul.”

We see a revival of this same legal drama now in the Trump administration’s aggressive and intensifying attacks on the Justice Department’s senior ranks, the special counsel and the FBI. It serves the defense’s purpose of diverting attention from the merits of claims to the process that generated them. In other contexts, this is a standard legal defense strategy. In this situation, the approach confuses the issue and lets Congress off the hook.

Of course, a president can also question the motives of congressional critics eager to resort to impeachment. However, where the impeachment process is dependent on the work of the special counsel, the executive’s defenders can plausibly charge the Congress with delinquency in the performance of its constitutional role. They will likely claim that the legislature has “outsourced” its investigative function, and the core judgment of the existence of a potentially impeachable offense, to an unreliable, politically suspect third party.

This view—that, if criminal prosecutions cannot end in indictment, they may launch and structure the impeachment process—poses distinct problems for a workable and accountable constitutional procedure. It encourages a peculiar role for the special counsel who must manage concurrent responsibilities to the Congress and to the executive. It leads Congress to effectively delegate to the special counsel the bulk of the work of investigating the basis for impeachment. As in the Starr case, the legal process is yoked to the politics of the impeachment. How and whether Congress acquires the case file, or what steps it takes to benefit from it, become major issues.

From that point on, the impeachment process concerns what the special counsel, barred from bringing an indictment, has done and how well he has done it. The inquiry becomes as much a judgment about his work as it is about the president’s conduct. From the relevant perspectives—separation of powers or the integrity of the impeachment process—this seems a bad result.

The more appropriate, “cleaner” answer is for each branch to do its constitutionally assigned job. The special counsel investigates, and if the evidence supports an indictment, he brings one. The Congress judges from this and other sources whether to initiate an impeachment inquiry. It is not lacking in the capacity to conduct investigations, and it is able to appoint an experienced prosecutorial team of its own to supplement the resources already at hand. To the extent that Congress draws on the special counsel’s case, it will benefit from investigations conducted, and legal conclusions reached, through the normal workings of the criminal justice process. The executive and the legislative branches are each responsible for performing their assigned responsibilities and answering for them.

This understanding of roles also weakens the temptation for a special counsel to adopt dodgy strategies for indicting without actually indicting,—for example, naming the president as an “unindicted co-conspirator.” The criminal justice system is better off if the prosecutor makes his judgments in the ordinary course, as he would in any other case. The “unindicted co-conspirator” stratagem raises question about the counsel’s disregard for the lines that OLC has drawn. It is also unclear how this maneuver spares the president all the costs that OLC identifies in an indictment. Escaping indictment may better for the president and his legal position than being named as a co-conspirator, but would it really spare the president what OLC termed "the stigma and opprobrium associated with a criminal charge, undermining the president's leadership and efficacy both here and abroad"?

The Congress and special or independent counsels have in the past discharged their distinctive functions concurrently. The only question is whether the OLC opinion rightly blocks the special counsel from carrying out his law enforcement function, asking that we be reassured that his efforts will not go to waste in a manner consistent with "more general considerations of constitutional structure.” On this point, as elsewhere in its chain of reasoning, it stumbles.