For the past two and a half years of Donald Trump’s Presidency, I have consoled myself with the argument that, despite all the chaos and narcissism and racial incitement and norm-shattering, the American system of government is holding itself together. When Trump attempted to introduce a ban on Muslims entering the country and sought to add a citizenship question to the census, the courts restrained him. When he railed at NATO and loyal allies like Germany’s Angela Merkel, other members of his Administration issued quiet reassurances that it was just bluster. When the American people had the chance to issue a verdict on Trump’s first two years in office, they turned the House of Representatives over to the opposition party.

All of this was reassuring. But, while watching what happened on Capitol Hill on Wednesday, when Robert Mueller, the former special counsel, testified before two House committees, I struggled to contain a rising sense of dread about where the country is heading. With Republicans united behind the President, Democrats uncertain about how to proceed, and Mueller reluctant to the last to come straight out and say that the President committed impeachable offenses, it looks like Trump’s blitzkrieg tactics of demonizing anyone who challenges him, terrorizing potential dissidents on his own side, and relentlessly spouting propaganda over social media may have worked. If so, he will have recorded a historic victory over the bedrock American principles of congressional oversight and equality before the law.

The morning session was largely devoted to Volume II of Mueller’s report, in which he relates ten instances of Trump seeking to interfere with the Russia investigation. Sitting before them, the G.O.P. members of the House Judiciary Committee had a seventy-four-year-old registered Republican and decorated hero of the Vietnam War, who subsequently spent decades as a public prosecutor, was appointed to the position of F.B.I. director by George W. Bush, in 2001, and served twelve years in that post. Yet some of the Republican members of the Committee treated their distinguished witness with thinly disguised contempt.

Louie Gohmert, of Texas, who has made a career of scaremongering, gay-bashing, and Islamophobia, began his questioning by entering into the congressional record a screed he authored titled “Robert Mueller: Unmasked.” Matt Gaetz, of Florida, sneered at the former special counsel as he sought, unsuccessfully, to get him to comment on the conspiracy theory that the allegations against Trump in Christopher Steele’s Russia dossier were part of a Russian government disinformation campaign. Ohio’s Jim Jordan threw his arms in the air and mocked Mueller for his refusal to answer questions about Joseph Mifsud, the mysterious Maltese professor who allegedly told George Papadopoulos, a Trump campaign aide, that the Russians had damaging material on Hillary Clinton. John Ratcliffe, another Texan, asked why Mueller bothered to write his report at all, given the Justice Department guidelines that say a sitting President can’t be indicted on criminal charges. Wisconsin’s Jim Sensenbrenner went further, questioning whether Mueller should have even carried out the investigation, which he described as “fishing.”

Yet none of these Republicans questioned any of the factual accounts of Trump’s behavior contained in Mueller’s report, which included attempting to fire Mueller, and, when that effort failed, trying to get the Attorney General to limit the special counsel’s remit. Rather than trying to refute Mueller’s findings, the Republicans sought to switch attention to the origins of the Russia investigation, which is, of course, precisely what Trump has been doing for the past two years.

The wanton disrespect that these elected Republicans showed Mueller was perhaps the most alarming testament yet to Trump’s total conquest of the Party. In today’s G.O.P., as in Stalin’s Russia, evidently, decades of loyal public service count for nothing when the leader and his henchmen decide someone represents a threat and the apparatchiks have been ordered to take that person down. All that matters is carrying out the order and staying in the leader’s good graces. That isn’t congressional oversight. It is scorched-earth politics of a kind that is entirely antithetical to the notion of checks and balances enshrined in the U.S. Constitution.

It was left to the Democratic members of the committee to remind the millions watching about the Bronze Star that Mueller received for rescuing a wounded fellow-marine while under enemy fire, and the fact that the U.S. Senate confirmed him and reconfirmed him unanimously to the F.B.I. job. Mueller was too modest to mention any of this. Sadly, and for whatever reason, he also seemed reluctant to return the Republicans’ fire in like fashion. Particularly in the morning hearing, he appeared hesitant. Many times, he asked for a question to be repeated. About the only occasion in which he displayed some genuine passion was in defending his colleagues on the Russia investigation, whom the Republicans—again, taking their lead from Trump—were trying to portray as Democratic political operatives.

Sticking to his promise not to stray beyond the contents of his report, Mueller frustrated the Democrats’ hope that he would bring the lengthy document to life. In confirming the damning accounts of Trump’s actions, which Democrats read out, he answered, simply, “Yes,” “True,” or “That’s correct.” When Ted Lieu, a California Democrat, asked him to read out a section of the report, he declined.

Despite Mueller’s reticence, the Democrats succeeded in countering the White House’s messaging, and showed that the report provides ample legal justification for opening an impeachment inquiry. In his opening statement, Mueller undermined months of White House obfuscation, saying, “We did not address collusion, which is not a legal term.” And, during his initial exchange with Nadler, the former special counsel completed the demolition job by stating unequivocally that his report hadn’t exonerated Trump on the obstruction question.

There was more. Toward the end of the morning session, Hakeem Jeffries, a Democrat serving Brooklyn and Queens, seemed to get Mueller to confirm that Trump’s effort, in the summer of 2017, to have Don McGahn, then the White House counsel, fire him satisfied the three requirements for a criminal indictment: an act that is obstructive, a link to an official proceeding, and corrupt intent. Also, Lieu twice got Mueller to say that the reason he didn’t press charges was the Justice Department’s guideline that rules out such a course of action. Unfortunately for the Democrats, Mueller subsequently clarified this statement, which went further than anything he had said in his earlier answers, or in his report. “That is not the correct way to say it,” he said at the start of his afternoon appearance before the House Intelligence Committee. “As we say in the report, and I said at the opening, we did not reach a determination on whether the President committed a crime.”

Even after this clarification, however, the overriding impression that Mueller left was that the President knowingly attempted to obstruct his investigation, and that such attempts can be criminal even if they don’t succeed. In the afternoon session, he also left hanging the question of whether Trump made false statements to the investigators, affirming “generally” that the President’s written answers to his questions weren’t always truthful.

The tragedy is that this might not matter. Even as Mueller was still testifying, some media commentary was intimating that his appearance wouldn’t change anything. “Those who wanted to begin impeachment proceedings needed bombshells from the former special counsel,” Politico’s Playbook newsletter said. “Mueller gave them nothing besides affirmation about what was in his report, and a series of sidesteps when he did not want to answer questions.” Later in the afternoon, the Washington Post’s Aaron Blake wrote, “If Democrats hoped this would be a seminal moment, they will apparently leave sorely disappointed—in large part because their star witness was no star.”

It is now up to the House Democrats. Leaving a meeting of her caucus on Wednesday afternoon, Speaker Nancy Pelosi told reporters, “The American people now realize more fully the crimes that have been committed against our Constitution.” But, in a subsequent press conference, she indicated that a move toward impeachment wasn’t imminent. “We still have outstanding matters in the courts,” she said.