Senator Jeff Merkley was right about the problem with any nomination Donald Trump was going to make for the Supreme Court at this low point in the president’s troubled tenure. “A President under investigation should never be allowed to appoint a Justice to the Supreme Court,” the Oregon Democrat argued before Trump announced on Monday night that he had selected federal judge Brett Kavanaugh to fill the vacancy created by the retirement of Justice Anthony Kennedy.

Merkley’s objection was generally appropriate, in light of the ongoing inquiry by special counsel Robert Mueller into wrongdoing by the president’s associates—and, potentially, Trump himself. But it is especially appropriate with regard to Kavanaugh.

A former staff secretary in the Executive Office of the President of the United States under President George W. Bush, Kavanaugh now serves on the United States Court of Appeals for the District of Columbia Circuit. He is a rigid right-wing ideologue who, if confirmed, would move the court far to the right. “The president pulled Judge Kavanaugh’s name from a pre-approved list concocted by radical, far-right special interests that are committed to undermining a woman’s right to choose, health care protections, safeguards for workers and seniors, LGBTQ rights, and a host of other critical public protections that touch the lives of every New Mexican and every American,” explains Senator Tom Udall (D-NM). “These extreme groups put Judge Kavanaugh’s name on their list for a reason.”

But believers in the rule of law should be concerned that something else about this nominee appealed to Donald Trump. Kavanaugh has been an open advocate for precisely the sort of imperial presidency that the founders of the American experiment feared—and that Donald Trump relishes.

There is open speculation that Trump’s grip on the presidency is threatened by the special counsel’s investigation. But the high court could avert that threat. And Trump has every reason to believe that his nominee could tip the balance of a closely divided court in his favor. As Bloomberg News has noted, “Kavanaugh addressed some of the constitutional issues that could emerge from an investigation like Mueller’s in a 2009 Minnesota Law Review article.” What Kavanaugh wrote three years after he assumed his current position on the DC Circuit ought to trouble everyone who believes that the president is a servant of the people, rather than “a king for four years.”

“I believe it vital that the President be able to focus on his never-ending tasks with as few distractions as possible. The country wants the President to be ‘one of us’ who bears the same responsibilities of citizenship that all share. But I believe that the President should be excused from some of the burdens of ordinary citizenship while serving in office,” argued Kavanaugh in the law-review article. He then asserted that “the indictment and trial of a sitting President, moreover, would cripple the federal government, rendering it unable to function with credibility in either the international or domestic arenas. Such an outcome would ill serve the public interest, especially in times of financial or national security crisis.”

That statement anticipated Rudy Giuliani’s most over-the-top defenses of President Trump. And, as with Giuliani’s rants, Kavanaugh’s arguments reject history, legal precedents, and the logic of a system that is supposed to place the rule of law over the rule of men.

Kavanaugh did not always embrace a monarchical interpretation of the presidency. He worked with independent counsel Kenneth Starr during the period leading up to the 1998 impeachment of former President Bill Clinton. But Kavanaugh has since suggested that he was mistaken to believe “that the President should be required to shoulder the same obligations that we all carry.”

“Looking back to the late 1990s, for example, the nation certainly would have been better off if President Clinton could have focused on Osama bin Laden without being distracted by the Paula Jones sexual harassment case and its criminal investigation offshoots,” mused Kavanaugh in his law-review article, which proposed that “Congress might consider a law exempting a President—while in office—from criminal prosecution and investigation.”

Kavanaugh can be accused of hypocrisy. But he will not be accused of pulling his political punches when it comes to promoting an imperial presidency with lines like “No single prosecutor, judge, or jury should be able to accomplish what the Constitution assigns to the Congress.”

In his law-review article, Kavanaugh speculated that his approach would not place presidents entirely above the law, because inquiries and indictments would simply be deferred until the end of a scandal-plagued presidency. He also noted that impeachment would remain an option for addressing “dastardly” acts by a commander in chief.

But, of course, delaying legitimate and necessary legal accountability does place a sitting president above the law. And suggesting that accountability can be achieved only via impeachment marginalizes the legal processes that past presidents have respected.

Kavanaugh’s extremism demands questioning along the lines proposed by Senate Judiciary Committee member Richard Blumenthal (D-CT), who has suggested that he might ask Trump’s nominee, “Will you commit that you’ll recuse yourself, because you’re being appointed by a president who’s likely to have that litigation?”

Blumenthal acknowledges that a Trump nominee is unlikely to discuss any give-and-take he might have had with the president on accountability issues. But CNN White House correspondent Jim Acosta reports that his network has confirmed that the “Trump SCOTUS team has looked at Kavanaugh’s past comments on indicting a sitting president.”

This combination of facts—a president who is under scrutiny choosing a Supreme Court nominee who he certainly knows is disinclined toward holding presidents to account—is not merely unsettling. Without an absolute and unequivocal commitment to recuse from any deliberations involving Trump’s alleged wrongdoing, which no one expects Kavanaugh to make, this nomination cannot possibly be seen by Democrats or Republicans, liberals or conservatives, as a credible choice to serve on the Supreme Court.

Brett Kavanaugh’s nomination must be understood as the product of a corrupt process that is, by its nature, disqualifying.

“Should this president be able to put people in place that can then come back and protect him?” Senator Cory Booker (D-NJ) asked after Kennedy announced he was stepping down. Describing Trump as “a president who has asked for loyalty tests, who has asked for litmus tests,” Booker answered the question he had posed with a blunt declaration that “I just wouldn’t do it.” Now that Brett Kavanaugh has been nominated, that should be the answer of every senator.