Laurence H. Tribe is Carl M. Loeb University Professor and Professor of Constitutional Law at Harvard Law School

My friend Alan Dershowitz has restated in Maclean’s his now familiar arguments against holding a sitting president fully accountable for abusing his executive powers. As I and other constitutional scholars have explained, those arguments don’t withstand scrutiny. They rely on the strange idea that, because the president is head of the executive branch, and because the three branches are supposed to be independent of one another, nothing the president does in his purely executive capacity, like granting a pardon or firing a subordinate, can be part of a criminal or impeachable obstruction of justice.

That simplistic idea cannot be squared with such leading Supreme Court decisions as the unanimous ruling in United States v. Nixon (1974), requiring the president to cooperate as an unindicted co-conspirator with the prosecution of his own subordinates by turning over incriminating tapes of Oval Office conversations, and the 7-1 ruling in Morrison v. Olson (1988), upholding the power of Congress to create an independent special prosecutor to investigate and prosecute criminality high in the executive branch and to provide that the special prosecutor or independent counsel cannot be fired by anyone in that branch – even at the president’s direction – without proof of the special prosecutor’s misconduct.

Of course decisions like those two limit the theoretical independence and autonomy of the president as head of the federal executive branch and cut into the notion of what some call the “unitary executive,” a term that to the framers signified that there would be but one president at a time and not a multi-headed presidency (a limitation that the Trump Transition seems to have overlooked in trying to undermine Obama’s foreign policy before assuming office). But, as the great Justice Robert H. Jackson famously wrote in explaining his vote to strike down President Truman’s nationalization of our country’s steel industry during the Korean conflict in his role as Commander in Chief without congressional permission, the Constitution “enjoins upon [the federal government’s] branches separateness but interdependence, autonomy but reciprocity.”Youngstown Sheet & Tube Co. v. Sawyer, 343 U.S. 579, 635 (1952).

Proponents of Alan’s view, who are (it must be said) few in number and are mostly on Trump’s legal team, like to cite Justice Scalia’s opinion in Morrison but typically fail to note that the opinion they invoke was a solo dissent. The majority opinion, written for all the remaining justices by Chief Justice Rehnquist, emphatically rejected the position that a president must retain “unfettered discretion” to control and even remove someone appointed to carry out “law enforcement functions” typically performed by someone fully answerable to (and removable at will by) the president.

Once it is conceded that the president can be prosecuted criminally and even impeached by the House and convicted by the Senate for giving or accepting a bribe in order to prevent investigation and prosecution either of those close to him or of himself – a concession that Alan Dershowitz appears to make from time to time – maintaining that the president’s motives in firing the FBI Director or getting rid of a Special Counsel like Robert Mueller are constitutionally irrelevant is senseless.

A president who offers to keep the FBI Director in his job if but only if the Director agrees to “go easy” on a national security director who has lied to the FBI about his dealings with a hostile foreign power is both offering a bribe and obstructing justice. And, if he does so with the motive of covering up his campaign’s conspiracy against the United States in orchestrating foreign interference with our presidential election, that president is engaged in a particularly pernicious form of obstruction whether or not the technical requirements for the federal statutory crime of bribery have been met.

The same would be true in spades if the President were to engineer a Mueller Massacre to rid himself of what he clearly sees as a meddlesome investigation into foreign activities that he fears might undermine the legitimacy of his presidency. Placing presidential pride above the nation’s sovereignty is a grave abuse of presidential power by anyone’s definition. To insist that the proceedings against such a lawless president be categorized under some heading other than obstruction of justice is to reduce a grave matter of national security and the rule of law to a trivial word game.

Having made these points, I’m uninterested in protracting this disagreement or going back and forth over the same well-trod legal territory. My view of Alan’s position, like Gertrude Stein’s view of Oakland, can be stated simply: There’s no “there” there.

I do want to note for the record, however, a particular mistake that I don’t recall Alan making in earlier iterations of his position but that he has made in his latest publication in Maclean’s. To explain his understanding of the separation of powers and its implications for his denial that President Trump could ever be prosecuted (or impeached, though Alan is less clear on that score) for how he performs his “constitutionally authorized duties,” Alan invokes the special shield the Constitution accords to members of the House and Senate in performing their official functions. He then equates that shield with the sweeping immunity he claims the Constitution gives the president even when the president’s means of, or motives for, exercising his executive powers (to pardon someone or to get rid of a federal prosecutor, for instance – presumably including Special Counsel Robert Mueller) are demonstrably corrupt or otherwise unlawful.

That’s an equation the Constitution refutes rather than supports. I say that because the congressional immunity on which Alan relies is expressly written into the Constitution’sSpeech or Debate Clause (Article I, Sec. 6, Cl. 1), which protects members of both the House and Senate from arrest while attending sessions of their respective Houses “in all Cases, except Treason, Felony and Breach of the Peace” and provides that “for any Speech or Debate in either House, they shall not be questioned in any other Place.” Professor Dershowitz must surely be aware that this unique constitutional rule is the reason the motives of Senators and Representatives cannot be called into question as a basis for imposing civil or criminal liability on those officials for abusing their powers.

In contrast, the rule Alan would create out of whole cloth for the president can be found nowhere in the Constitution’s text, structure, or history. It would, in fact, create an anomalous exception to the general principle that all public officials in the United States are responsible, in appropriate proceedings, for using their powers to aggrandize themselves or for other corrupt purposes.

I have no interest in engaging Alan in a seemingly unending back-and-forth about this point. I take him at his word that he genuinely believes the argument he has advanced and am not questioning his motives. I would question, though his parting statement, made at the close of his latest piece, that “some of [his] friends on the left” have criticized him “for placing constitutional principles above partisan consideration,” a charge to which he “proudly plead[s] guilty.” Professor Dershowitz has been criticized not for putting constitutional and legal principles above partisan politics but for misunderstanding and distorting those very principles, inventing rules that have no genuine support in the Constitution’s text, structure, or history or in the views of leading constitutional scholars.

MORE ABOUT UNITED STATES: