The word unprecedented applies to so many aspects of Judge Brett Kavanaugh’s nomination to the Supreme Court of the United States. From the threat his confirmation poses to many of the rights we hold dear, to the withholding of thousands of documents from the public on spurious grounds, to Kavanaugh’s persistent dissembling before the Senate Judiciary Committee—the list seems endless.

Democrats are fighting to expose Kavanaugh’s extreme right-wing ideology and the deeply flawed process by which his nomination is being hurried through the Senate. But the inside game effectively has an audience of two. Unless Sens. Susan Collins and Lisa Murkowski are moved by Kavanaugh’s apparent perjury and the near guarantee that Kavanaugh will provide the deciding vote to end a woman’s right to choose, we are almost certain to see Kavanaugh elevated to the high court.

While last week’s hearings proved rougher sledding than expected for Kavanaugh, we must prepare for the prospect of Judge Kavanaugh becoming Justice Kavanaugh. That is where another unprecedented element of this nomination comes into play. This will be the first time in American history that a president who many have described as an “unindicted conspirator” in high crimes and misdemeanors has had the chance to hand-pick a vote on the Supreme Court, including in matters that involve him.

And that is where the audience of GOP senators who might break ranks expands beyond just Collins and Murkowski. Sens. Bob Corker, Jeff Flake, and Ben Sasse have all taken President Trump to task for his worst impulses and acts. They seem to see the existential threats he poses. They have consistently pinpointed those in public statements and speeches. Given the revelations from the White House this past week about the president’s dangerous lack of comprehension or control, and his material threats to the rule of law that each senator has condemned in public, the time has come for them to take at least some concrete steps to protect the country.

Corker, Flake, and Sasse could impose a single simple condition on Kavanaugh: They can insist that he recuse himself from any case involving the special counsel, subpoenas and/or depositions of executive-branch members, pardons of Trump’s co-conspirators and himself, or a unitary executive’s powers.

All three senators have made clear this week that they admire and support his nominee for his temperament and record. In ordinary times, that would be the end of the matter. But if these three senators believe the current president must be constrained and checked in his aspirations for absolute executive power, they hold in their hands the power to check him. This would not require voting against Judge Kavanaugh. But it would demand that they attempt to use their votes to cabin Trump’s lawless impulses. Democrats alone cannot force that to happen. Any two Republican senators can.

So far, their criticism of the president has been eloquent and passionate, but it has effectuated exactly no meaningful change.

As Sasse noted frequently during the hearings, Congress is not doing the job it was tasked with by the Framers. In lieu of Congress providing real checks and balances, any sober observer—including Corker, Flake, and Sasse—must see that the courts are the most significant remaining bulwark standing between us and autocracy. And the president is poised to put the fifth and deciding vote on several matters of enormous national import onto the Supreme Court.

Judge Kavanaugh has expressed more extreme views of presidential power than any Supreme Court nominee in our history. Through his long career, his writings and speeches have shown that he does not believe the president can be forced to comply with a subpoena. He does not believe the president can be subjected to criminal or civil proceedings while in office. And he is among the most extreme proponents of the “unitary executive”—the theory that the president has total power to control the entire executive branch, which would include his ability to fire his prosecutors, obstruct justice, and more—on any level of the federal bench. Kavanaugh has said nothing in this week’s hearings to suggest that he is aware of the president’s boundless view of his own power; indeed the nominee has declined to even discuss this president’s claims about his executive authority.

It is folly to believe that the judge’s extreme executive-power beliefs were lost on the president when Kavanaugh—who was not even under consideration for the seat filled by Justice Gorsuch—was anointed as the nominee. The president, after all, is now subject to multiple criminal investigations and civil lawsuits. It is hardly unimaginable that Donald Trump believed he could protect himself by nominating a justice who believes in extraordinarily broad presidential power. Nor does one have to reach far to imagine these issues being discussed privately with Judge Kavanaugh before he was selected. While he declined to discuss it in his hearings, one of his close friends works for the law firm that once represented Trump on these issues.

Under these circumstances, should Kavanaugh be confirmed, and should he participate in cases involving this president’s power to protect himself from legal investigation, we don’t just risk delegitimizing the Supreme Court. We risk delegitimizing our entire democracy. The Senate is poised to confirm the person who will decide, in the foreseeable future, whether this president is above the law. The nominee refuses to discuss this possibility, and that is his prerogative. But senators are not required by any ethical rules to pretend that this scenario may not ever happen. They are, in fact, obligated by their oaths of office to at least imagine that it will.

This week, Judge Kavanaugh refused to discuss whether he would recuse himself from any such cases and to explain what his standards for his own recusal would be, claiming, “If I committed to deciding a particular case, which includes committing to whether I would participate in a particular case, all I would be doing is demonstrating that I don’t have the independence of the judiciary.” So not only is he refusing to discuss his own conflicts of interest around the president, he is also declining to commit to avoiding them. That is his prerogative. But senators certainly can wield their own considerable clout to seek answers as to whether the president’s claimed immunity from any investigation, or suit, or any legal consequences—claims Trump proffers regularly—will be decided by a justice who has already made clear in his writings and speeches that at least in principle he supports such claims.

This is a low bar. GOP senators should exercise their substantial oversight powers far more than the Senate is currently doing. They should investigate and expose the president’s ties to Russia. They should protect the Mueller investigation (as several Republican senators have suggested). They should work to ensure that elections remain free and fair. They should have insisted on delaying the Kavanaugh hearing until his full record had been released and examined. They should stop the Kavanaugh nomination entirely. And they really should caucus with the Democrats to ensure all of the above actually happens. For now at least, instead, none of that is going to happen.

But, Corker, Flake, and Sasse have spoken forcefully on behalf of checks and balances, on behalf of constitutionally constraining institutions and the rule of law. So far, their criticism of the president has been eloquent and passionate, but it has effectuated exactly no meaningful change. To the contrary, when Trump’s attacks on the law and on his own Justice Department lead solely to sound and fury followed by inaction, it seems to embolden this president to further lawlessness. These senators have within their power the chance to protect the Senate and the Supreme Court from a president who has shown contempt for both. Demanding Kavanaugh’s recusal on matters involving this president personally is the tiniest of steps they could take toward protecting our democracy while keeping faith with President Trump and their Republican brethren.