Special Counsel Robert Mueller today made a surprise public statement, nearly six weeks after the public release of his report on the Russia investigation. He announced that the special counsel’s office was formally closing, that its investigation was complete and that he was resigning from the Department of Justice. This was not a huge shock.

Less expected was Mueller’s announcement that he didn’t intend to make any further statements—not even before Congress in testimony that has been much anticipated. Mueller said he “hop[ed] and expect[ed]” he would not speak about the matter further and that “[t]he report is my testimony.” If called by Congress to testify, he said he “would not go beyond our report.”

In other words, that’s all folks. As far as Mueller is concerned, he has no further role to play here.

Which is not to say that Mueller suggested that the story is over. Rather, the gravamen of Mueller’s comments squarely puts the question of what to do about the president’s conduct in Congress’s hands, not his own.

Mueller declared that his office had chosen its words carefully and that the report speaks for itself—his version of screaming, “Just go read the actual report!” in the general direction of Capitol Hill. And he concluded his remarks by “reiterating the central allegation of our indictments—that there were multiple, systematic efforts to interfere in our election. That allegation deserves the attention of every American.”

He was more explicit at times too. As in his report itself, he did not declare that the president had committed crimes. But he also made clear once again that “if we had confidence that the President clearly did not commit a crime we would have said that.” And he noted again that the Justice Department’s Office of Legal Counsel had determined “that the Constitution requires a process other than the criminal justice system to formally accuse a sitting President of wrongdoing.” In other words, the remedy here is not the criminal justice system. The remedy is congressional in character—impeachment, if Congress considers that appropriate, but not indictment or further words from Robert Swan Mueller III.

All of which raises serious institutional questions for Congress. House judiciary committee Chairman Jerry Nadler tweeted in response to Mueller’s remarks that “it falls to Congress to respond to the crimes, lies and other wrongdoing of President Trump.” That’s correct.

But what does a reasonable congressional response look like?

Nadler was being overwrought a few weeks ago when he declared President Trump’s defiance of congressional oversight efforts a “constitutional crisis.” Whatever a constitutional crisis may be, and I confess I have never been quite sure, it certainly does not include a situation in which the House of Representatives does not trouble itself to exercise its undoubted constitutional impeachment powers against a president about whom it prefers merely to complain.

But the standoff between the White House and the House committees that would investigate the president does represent a crisis of sorts; call it a crisis of oversight. At stake is whether this president will, and future presidents will have to, take congressional oversight demands seriously when those demands involve presidential conduct or touch matters about which the president cares personally. At stake is also the question of what, if any, case law or threat of congressional action will back up such demands now or in the future.

And at stake as well is the question of impeachment. House Speaker Nancy Pelosi, after all, has resisted impeachment proceedings on the theory that the House should investigate first and move toward impeachment only as public opinion and the facts demand. Denuding the investigative process of any vitality makes the impeachment question stark indeed—a road one either takes or does not take, but which one cannot explore thoughtfully in any fashion that might require factual development. The standoff, in short, poses the question of congressional capacity to investigate the executive when matters really count.

Now that Mueller is not going to show up and report live before the judiciary committee, that question has become dramatically more acute.

The current crisis of oversight poses other important questions with Mueller so dramatically taking himself out of the picture: Since the Trump administration has made it abundantly clear that it will not cooperate with routine congressional follow-up to the Mueller report, what questions does Congress really want to explore and which questions are less important? Is the goal to break new factual ground in one area or another? Is it to evaluate Trump’s conduct? Is it to establish a factual record to support some piece or pieces of legislation? Is it to set the table for impeachment? Or is it to dramatize and bring to life the 448 pages of the Mueller report—which Mueller has now made clear he will not be bringing to life himself—and, as Trump might put it, see what happens?

Congress’s current strategy is an incoherent muddle. While individual Democratic leaders may well have their eye on the ball, the aggregate output of disparate committee chairs has reflected no discernable strategy. Some, judging from their statements, seem focused chiefly on getting the full, unredacted Mueller report and the investigative work product that underlies it. Why exactly this is the focus is unclear to me; the marginal information Congress is likely to glean from the full report is small. Much of this material is already available to certain members under admittedly limited conditions. And the legal impediments to the production of the remainder are substantial. Focusing on laying bare what is currently redacted is most unlikely to produce any game-changers. Other than establishing the principle that Congress can get it, it’s not clear what great oversight interest it serves.

At the same time, the key committees have shown only limited interest in unpacking in public the voluminous material that Mueller has publicly reported and that is thus readily available for discussion. As of today, this requires a major rethink. Mueller himself is not riding in on a white horse to explain it all. If Congress is going to highlight what’s in that report and what Mueller found, it’s going to have to do it on its own.

The absence of public hearings on the contents of the Mueller report can be blamed only in part on Don McGahn’s decision to honor the president’s claims of executive privilege and defy the judiciary committee’s subpoena. A big part of the story here is that key committees are just not pursuing a focused oversight agenda involving live testimony by the key witnesses in a fashion that is likely to prove effective. Congress has so far sought the testimony of relatively few people named in the report. It has not so far moved aggressively against anyone who has resisted.

This lack of focus on getting testimony from witnesses has combined with a deep commitment on the part of the Democratic leadership not to use the most substantial powers that it has—specifically the impeachment power. The congressional leadership seems not to know quite what it wants, but it sure knows what it doesn’t want. That’s not a good posture in which to confront a concerted presidential challenge to the very possibility of congressional investigation of executive conduct.

Trump’s challenge to congressional oversight is multifaceted, and the facets are not all of comparable seriousness. The president asserts a broad claim of authority to evaluate the legitimacy of the legislative purpose behind congressional subpoenas—a cross-cutting claim that would affect nearly all of Congress’s requests for material. He makes sweeping assertions of executive privilege, which range from frivolous to quite plausible. The administration refuses compliance with subpoenas even where clear statutes specifically require the production of the information in question.

To confront this challenge, particularly now that it cannot rely on Mueller, Congress needs to prioritize. Members need to figure out what they are trying to achieve—both in terms of what sort of information they are seeking to develop and in terms of what principles of inter-branch relations they are trying to establish.

Right now, at least in my view, key committees are barking up the wrong tree. Members seem very keen on establishing the principle that they can get the whole Mueller report, along with the investigative work product that supports it. This emphasis is misplaced for at least two reasons. The first is that, as I mentioned above, the amount of new information it is likely to generate is not all that great. The public already has access to the overwhelming body of Mueller’s work. The administration has offered to share nearly all of the rest—all but the passages redacted for reasons of grand jury secrecy—with congressional leaders, albeit under restrictive conditions. The House leadership could easily satisfy itself that there aren’t additional bombshells in the document, and if it turns out that there is additional material that has been withheld unreasonably, the Speech and Debate Clause would protect its disclosure in a floor speech, whatever commitments members may have made in order to get access.

The second reason is that the legal fight over the disclosure of grand jury material is an uphill climb. I have litigated for the release of grand jury material. Color me skeptical that the House is likely to prevail in a fight with the Justice Department over the disclosure of grand jury material, at least not in the short term and at least not while cases remain pending. The intelligence committee may be differently situated from the rest of the House, but if House members are taking the view that the average member needs to be able to see the whole report, there is just no prospect of obtaining this outcome in any reasonable time frame.

As to the underlying investigative work product, that is the sort of material that the Justice Department traditionally takes great pains to protect—and should protect. Devin Nunes was wrong to go after such material, and normalizing such misconduct is not a good idea now either.

In other words, fighting over the redactions in the Mueller report is a legal slog; it risks doing institutional damage; and it’s not likely to produce much that’s useful—especially because much of the redacted information is, in any event, available already to congressional leadership.

The better approach, in my view, is to focus on live testimony from witnesses who supplied the material about President Trump’s conduct that Mueller made public in the report—mostly but not exclusively in Volume II. There are a lot of these witnesses. Congress could easily hold weekly hearings that would be riveting television. Who knows? They might even get what the president most values in the world: good ratings. The goal would be to focus public attention on the president’s abuse of the intelligence and law enforcement communities and his individual conduct with respect to Russia. Such hearings could develop new information. They could also enrich our understanding of the existing factual record. They would serve to publicly validate and elucidate Mueller’s findings and, critically, to shift those findings from the voice of Mueller himself to the voice of the president’s closest aides. Perhaps most importantly, they would create a sustained vehicle for focusing on Trump’s conduct—which is, and needs to be, the central issue.

If I were in charge of the House judiciary committee, a wide array of witnesses named in the report would receive an invitation for public testimony—and any of them who did not immediately agree to appear would receive a subpoena in short order. The idea would be to bring the Mueller report to life and, along the way, to establish clearly in case law the ability of Congress to conduct such oversight hearings against a recalcitrant executive.

To accomplish this, the committee would need to deal with three major threshold legal issues, and it would need to be clever and agile and nonideological in doing so. The first issue is that cross-cutting legal claim Trump keeps making that none of the congressional inquiries he is facing has a legitimate legislative purpose. This claim is so weak legally that it will likely collapse of its own weight as courts continue to confront it. Judge Amit Mehta rejected it the other day in a case involving the House oversight committee’s efforts to get Trump’s financial records from his accounting firm. Mehta wrote that “courts must presume Congress is acting in furtherance of its constitutional responsibility to legislate and must defer to congressional judgments about what Congress needs to carry out that purpose. To be sure, there are limits on Congress’s investigative authority. But those limits do not substantially constrain Congress. So long as Congress investigates on a subject matter on which ‘legislation could be had,’ Congress acts as contemplated by Article I of the Constitution.” Expect the D.C. Circuit to affirm this relatively quickly, thus clearing away some brush that potentially impedes all congressional efforts. Judge Edgardo Ramos of the Southern District of New York ruled similarly in a separate case earlier this month, refusing to enjoin Deutsche Bank from complying with congressional subpoenas for Trump’s financial records. Trump has appealed the case to the Second Circuit.

The second issue is the one that has so far prevented McGahn’s testimony: the White House claim of testimonial immunity for senior White House aides, including former officials. Jonathan Schaub’s excellent Lawfare article on this claim—which reflects an aggressive assertion on Trump’s part of a long-standing executive branch position—makes clear that the argument, while not trivial, has weak basis in case law; the only court to have considered the matter has rejected it decisively. And the claim is weaker still with respect to former officials than sitting ones. If Congress were able to establish that it can compel former White House officials to appear, let alone current ones, it would have a wealth of the key witnesses—few of whom are still in office—at its disposal. In other words, litigation over live testimony by McGahn, Hope Hicks and Annie Donaldson is far more important than sparring over production of the unredacted Mueller report. This issue is less cross-cutting than the legislative purpose litigation, since not all key witnesses are former senior White House aides (think of Corey Lewandowski, for example) and not all will obey White House instructions not to show up in any event. That said, failure to establish this point will hobble any investigative efforts involving noncooperative witnesses. And establishing it will open the floodgates of witness availability.

The third issue, executive privilege, is trickier and should be handled in the first instance by finessing the matter—not by charging into litigation. Some, but not all, of the key witnesses to the president’s obstructive conduct have nontrivial executive privilege claims. These are, after all, the president’s immediate White House staff being asked to testify about their advice to and conversations with the president himself. The White House is sure to assert executive privilege broadly, and while many of these claims could likely be defeated in lengthy litigation, time is not on Congress’s side to the extent it wants to focus now and publicly on presidential conduct. In other words, getting bogged down in litigation over executive privilege for each prospective witness is a bad idea.

The good news is that getting bogged down in such litigation is also wholly avoidable. The reason is that the privilege here is at least partly waived, insofar as the White House not only allowed these witnesses to talk to the Mueller investigation but then also allowed Attorney General William Barr to transmit Mueller’s report to Congress and the public. The White House might have arguments that material not contained within the four corners of the Mueller report remains privileged, but there is no colorable argument for an assertion of privilege over material the White House allowed Barr to make public with an express public statement that the White House had waived privilege. At his press conference releasing the Mueller report, Barr said specifically that:

the President confirmed that, in the interests of transparency and full disclosure to the American people, he would not assert privilege over the Special Counsel’s report. Accordingly, the public report I am releasing today contains redactions only for the four categories that I previously outlined, and no material has been redacted based on executive privilege.

In other words, there are 448 pages of the Mueller report about which no remotely plausible executive privilege claim remains.

That means something crucial: If the White House seeks to assert privilege with respect to any witness named in the report, the House need not litigate the matter. It can choose, at least as an initial matter, simply to limit the questioning of these witnesses to those matters specifically contained within the report itself and to reserve fights over broader testimony for later.

Mueller is not showing up. But he has given Congress a highly detailed guide—one might even call it a “road map”—to whom it needs to hear from and what questions they need to be asked.

Boiling all of this down, what emerges are a few simple guidepost principles for effective post-Mueller congressional oversight:

First, don’t focus on piercing the redactions in the report. Take the deal the Justice Department is offering and check out the almost wholly unredacted version on offer.

Second, focus instead on highlighting the presidential conduct described in the unredacted sections. Congress’s specific role right now is in holding live hearings that put flesh on the dry narrative bones of the Mueller report.

Third, focus litigation efforts—as the House is already doing—on obliterating the president’s claims that he gets to second-guess the legitimacy of Congress’s legislative purpose and then on establishing that there is no principle of testimonial immunity for White House aides.

Fourth, defer executive privilege litigation to the extent necessary by agreeing to limit questioning of White House aides to matters specifically covered by the Mueller report. Litigate later, if need be, over additional testimony from these witnesses.

Proceeding in accordance with these principles would give coherence to congressional investigative efforts. It would avoid getting bogged down in the quicksand in which Trump has sought to mire these efforts. And it would help as well to establish answers to some legal questions about Congress’s oversight powers about which lack of clarity currently is empowering Trump’s abuses.

It’s a shame that Mueller is not showing up. But Congress can make do without him.