President Trump has said that if the House were to impeach him despite his not having committed "high crimes and misdemeanors," he might seek review of such an unconstitutional action in the Supreme Court. On April 24, he tweeted that if "the partisan Dems ever tried to Impeach, I would first head to the U.S. Supreme Court. Not only are there no 'High Crimes and Misdemeanors,' there are no Crimes by me at all."

Yesterday, when asked by a reporter if he thinks Congress will impeach him, the president responded, "I don't see how. They can because they're possibly allowed, although I can't imagine the courts allowing it."

Commentators have accused Trump of not understanding the way impeachment works and have stated quite categorically that the courts have no constitutional role to play in what is solely a congressional and political process. Time magazine declared in a headline "That's Not How It Works," and Vox called the president's argument "profoundly confused."

Scholars also echoed the derision. The influential legal blog Lawfare wrote confidently that "The Supreme Court Has No Role in Impeachment," and my friend and colleague Larry Tribe, an eminent constitutional law scholar, called Trump's argument simply "idiocy," explaining that "the court is very good at slapping down attempts to drag things out by bringing it into a dispute where it has no jurisdiction."

Not so fast. Our nonlawyer president may be closer to the truth than his lawyer critics. In fact, the Lawfare blog noted that "Trump's suggestion of resorting to the Supreme Court to appeal an impeachment did not come out of nowhere. ... Alan Dershowitz recently made an argument along the same lines, writing in an essay on 'The Case Against Impeaching Trump' that '[w]ere a president to announce that he refused to accept the actions of the Senate in voting for his removal ... and that he would not leave office unless the Supreme Court affirmed his removal, the people might well agree with him.'"

However, my argument did not come from nowhere, either.

Two former, well-respected justices of the Supreme Court first suggested that the judiciary may indeed have a role in reining in Congress were it to exceed its constitutional authority. Justice Byron White, a John F. Kennedy appointee, put it this way: "Finally, as applied to the special case of the President, the majority argument merely points out that, were the Senate to convict the President without any kind of trial, a Constitutional crisis might well result. It hardly follows that the Court ought to refrain from upholding the Constitution in all impeachment cases. Nor does it follow that, in cases of presidential impeachment, the Justices ought to abandon their constitutional responsibility because the Senate has precipitated a crisis."

Justice David Souter, a George H. W. Bush appointee, echoed his predecessor: "If the Senate were to act in a manner seriously threatening the integrity of its results ... judicial interference might well be appropriate."

It is not too much of a stretch from the kind of constitutional crises imagined by these learned justices to a crisis caused by a Congress that impeached a president without evidence of "high crimes and misdemeanors." The president is not above the law, but neither is Congress, whose members take an oath to support, not subvert, the Constitution. And that Constitution does not authorize impeachment for anything short of high crimes and misdemeanors.

Were Congress to try to impeach and remove a president without alleging and proving any such crime, and were the president to refuse to leave office on the ground that Congress had acted unconstitutionally, there would indeed be such a constitutional crisis. And Supreme Court precedent going back to Marbury v. Madison empowers the justices to resolve conflicts between the executive and legislative branches by applying the Constitution as the supreme law of the land.

Recall that when a president has been impeached by the House, the Supreme Court's chief justice presides at his Senate trial and the senators take a special oath. This special oath requires each senator to swear or affirm that "in all things pertaining to the trial ... [to] do impartial justice according to the Constitution and the law" (italics added).

If the House were to impeach for a noncrime, the president's lawyer could make a motion to the chief justice to dismiss the case, just as a lawyer for an ordinary defendant can make a motion to dismiss an indictment that did not charge a crime. The chief justice would be asked to enforce the senatorial oath by dismissing an impeachment that violated the words of the Constitution. There is no assurance that the chief justice would rule on such a motion, but it is certainly possible.

No one should criticize President Trump for raising the possibility of Supreme Court review, especially following Bush v. Gore, the case that ended the 2000 election. Many of the same academics ridiculed the notion that the justices would enter the political thicket of vote-counting. But they did and, in the process, weakened the "political question" doctrine. The case for applying the explicit constitutional criteria governing impeachment is far more compelling than was the case for stopping the Florida recount.

So no one should express partisan certainty regarding President Trump's suggestion that the Supreme Court might well decide that impeaching a president without evidence of high crimes and misdemeanors is unconstitutional.

Alan M. Dershowitz is the Felix Frankfurter Professor of Law, Emeritus, at Harvard Law School. His new book is "The Case Against the Democratic House Impeaching Trump." You can follow him on Twitter @AlanDersh.