The response to the report, in turn, validates the fears of those concerned that a Republican Congress will never meaningfully restrain those instincts. Barr’s servile press conference on Thursday morning obliterated the last hope, from earlier in Trump’s term, that senior “wise men” in the executive branch would restrain him in any way either. The resistance by former White House Counsel Don McGahn to some of Trump’s most egregious demands—particularly to fire Mueller—was a crucial step toward the completion of this report. It’s hard to imagine Trump’s current staff and Cabinet of loyalists and acting appointees resisting him so firmly on any front. Indeed, his acting White House chief of staff, Mick Mulvaney, has defined his tenure by refusing to try.

Read: Trump’s guardrails are gone

The implications of these dynamics extend far beyond the Mueller inquiry itself. They are also apparent in the ongoing purge of the Department of Homeland Security, which is largely the result of resistance there to hard-line White House immigration proposals. They are evident in Trump’s effort to further erode the independence of the Federal Reserve Board by nominating such openly partisan and dubiously qualified individuals as Herman Cain and Stephen Moore. And these dynamics explain the Republican acceptance of Trump’s ever more openly xenophobic and racist language, such as insisting that “our country is full,” as he looks to stir white racial anxieties in advance of 2020.

The Mueller report may not dislodge significant elements of Trump’s electoral coalition, some of whom thrill to his behavior and others who accept it in the same implicit bargain as do Republicans in Congress. But it seems highly likely to reinforce the doubts of the nearly 55 percent of Americans who expressed unease, if not outright revulsion, about him as president through their votes for other candidates in the 2016 election and for Democrats in the 2018 House races.

In 2016, many of Trump’s voters, uncertain of him but desiring change and dubious of Hillary Clinton, consciously took a flier: According to exit polls, about one-fifth of his supporters said they doubted that he had the experience to succeed as president, and about one-fourth said they doubted that he had the temperament. (Those numbers were even higher among ambivalent college-educated white voters.) Especially after the brutal bill of particulars that Mueller identified about Trump’s behavior, those voters now face a reckoning on their choice. No member of Congress, no potential executive-branch appointee, and, above all, no voter can claim any illusions about what a Trump second term might look like, especially if enabled by a Congress fully controlled again by Republicans.

Mueller sent many signals in his report that, given his own legal constraints, he expected Congress to assume responsibility for imposing accountability for Trump’s behavior. But his report also shows the limits of relying solely on courts and prosecutors to uphold the rule of law, or to defend basic standards of morality, in government. After Mueller’s detailed catalog of Trump’s unacceptable, if not indictable, behavior, that responsibility more clearly than ever rests with voters.