Brett Kavanaugh appeared before the Senate Judiciary Committee on Thursday an angry, vengeful man. He was belligerent and partisan, blaming allegations of sexual misconduct on a conspiracy of Democrats and “leftists” on behalf of “the Clintons.” He was curt and dismissive, shouting over Democratic committee members. And he was evasive and dishonest, answering pertinent questions about alcohol consumption with petulant dissembling. “Yes, we drank beer. My friends and I, the boys and girls. Yes, we drank beer. I liked beer. Still like beer,” he said in response to Sen. Dianne Feinstein. In one exchange with Sen. Amy Klobuchar of Minnesota, he mockingly asked her (later apologizing) if she ever drank to excess, a major breach of decorum for the subject of a hearing, let alone a federal judge.

All of this was for an audience of one: President Donald Trump, who wanted Kavanaugh to fight back, given his own experience with allegations of sexual assault, which he continues to minimize and dismiss despite a large number of credible accusers. It worked. Trump was reportedly enthralled with Kavanaugh’s testimony and followed it with a declaration of support. “Judge Kavanaugh showed America exactly why I nominated him,” he said on Twitter. “His testimony was powerful, honest, and riveting. Democrats’ search and destroy strategy is disgraceful and this process has been a total sham and effort to delay, obstruct, and resist. The Senate must vote!” Republicans on the committee, bolstered by a similarly angry broadside from South Carolina Sen. Lindsey Graham during the hearing, doubled down on Kavanaugh, attacking Democrats for the process behind Christine Blasey Ford’s allegations and condemning their questioning of Kavanaugh as a disgrace to the reputation of the Senate itself.

On Friday, Kavanaugh was advanced by the committee on a party-line vote. But in a surprise, Arizona Sen. Jeff Flake asked Majority Leader Mitch McConnell to postpone the full Senate vote to allow for an additional FBI investigation. After Flake spoke to the full Senate Judiciary Committee, Sen. Lisa Murkowski declared her support for the delay, which means Kavanaugh may not right now have the votes for confirmation.

It is impossible to say what will happen next. Kavanaugh’s confirmation is still likely, but it isn’t certain. But however this drama ends, it’s been a mess. With his furious partisanship and snarling anger, Kavanaugh is now an extraordinarily toxic nominee. And the raw exercise of power behind his confirmation is itself a powerful blow to the legitimacy of the Supreme Court.

This turn of events wasn’t inevitable. Trump had other, credible, conservative nominees for the Supreme Court. And he might have been able to confirm them with some Democratic support, putting a bipartisan stamp on his judicial legacy. But while Trump brags frequently about his judicial record, he’s unengaged with the details of vetting and selecting nominees. Kavanaugh, like prior nominee Neil Gorsuch, had been placed on Trump’s short list by key adviser Leonard Leo, a major figure in the Federalist Society, a nationwide organization of conservative lawyers. Leo singled out his old friend Kavanaugh as a top contender for the Supreme Court seat left by Justice Anthony Kennedy and made his recommendation to the president. To the extent that Trump was engaged with the process, it was likely in response to Kavanaugh’s expansive views of executive authority and belief that presidents should be shielded from criminal investigation while in office.

After nominating him, Trump was hands off, ceding responsibility of vetting and selling the nominee to his advisers as well as Republican leaders in Congress. Which meant he was already disengaged as it became clear that Kavanaugh was an unpopular nominee facing an unusually difficult time in the Senate Judiciary Committee and was blindsided by the anger following Ford’s allegations. It’s only since those allegations that Trump has shown any real interest in Kavanaugh’s nomination, and then, it has been to pressure Republicans into an unyielding defensive crouch, even as Kavanaugh’s standing slipped with the public.

By yielding to the president on Kavanaugh and not pressuring Trump to withdraw him and send up a different nominee for easier confirmation, Senate Republicans have contributed to the poisoned atmosphere around this nomination process. McConnell, in particular, is so preoccupied with winning Kavanaugh’s confirmation that he has led his caucus into a situation where putting him on the bench might spark an unprecedented backlash in the upcoming midterm elections. And even if a Kavanaugh confirmation doesn’t change the short-term electoral picture, there are long-run consequences to pushing a divisive, partisan nominee into a powerful lifetime position.

Given the already unprecedented blockade of Merrick Garland, the presence of a Justice Kavanaugh would, for millions of voters, cement the Supreme Court as a narrow, factional power, meant to enhance one political party at the expense of another. In response, liberals may push for radical solutions that alter or dilute the power of the court, from impeaching Kavanaugh to expanding and “packing” the court with new members. Either move would bring about an institutional arms race, as parties responded with ever-escalating reforms.

With Brett Kavanaugh, what began as an almost typical Supreme Court nomination has become a singular event in modern American life, a point from which our politics will become even more polarized. We still can’t say if he’ll win confirmation, but we can say that his performance heralds the widening of our partisan fault lines.