Lame duck Arizona Sen. Jeff Flake has demanded a vote on a bill granting Robert Mueller for-cause protection, and he’s holding up judicial nominees to get his way. For multiple reasons, the Senate should not take up any such bill — it has zero chance of passing in the House, the president will veto it with absolutely no possibility of an override, Robert Mueller’s investigation is (hopefully) drawing to a belated close. But the overriding reason is that the bill, if made law, is flat out unconstitutional.

In 2017, Yale Professor Akhil Amar testified before the Senate that any law granting for-cause protection would violate the Appointments Clause. Since then, Northwestern Law Professor Steve Calabresi has sounded the same alarm. Nothing has changed, and, sadly, no one has answered their cogent argument.

The argument is intuitive, and was made by Justice Antonin Scalia in Morrison v. Olsen more than 30 years ago. If Congress grants Robert Mueller for-cause protection, the law will be unconstitutional on day one. For-cause removal makes it virtually impossible for anyone to supervise the officer benefitting from such protection. Hence granting Mueller such safeguards makes him a more powerful officer who is answerable to no one.

The Constitution has a rule for how powerful, independent officers must be appointed. The Appointments Clause signals that formidable officers, answerable and subordinate to no one within the executive branch, must be nominated by the president and confirmed by the Senate. There is a constitutional exception for “inferior” officers. But Mr. Mueller, armed with for-cause protection, would be the inferior of no one. He would be one of the most consequential and mighty officers in the federal government, for he would be investigating the president and his friends without any prospect of real supervision, much less control.

Moreover, by conferring for-cause protection on an existing officer, Congress essentially would be appointing Mueller to a new, substantially more powerful office. The reason is simple. If Congress sufficiently changes an existing officer’s authority, as the bill would do, you have essentially appointed the existing officer to a new office. Congress has no absolutely power to appoint officers of any sort.

Of course, Justice Scalia’s opinion was issued in dissent. But since that stirring dissent, history has been rather unkind to the Morrison majority. In several majority opinions, the court has signaled that Congress cannot bypass the ordinary process of presidential nomination and Senate consent for those officers who wield significant authority and are answerable to no one within the executive branch. In other words, the court has come rather close to endorsing Justice Scalia’s dissent.

Justice Elena Kagan, in a public speech, said that Justice Scalia’s Morrison opinion was “one of the greatest dissents ever written and every year it gets better.” Justice Kagan was absolutely right, and the court has all but announced that it agrees with Justice Scalia’s dissent.

The Senate should not be deaf to the blare of the multiple constitutional alarms, sounding from the court’s opinions and from the legal academy. As much as senators may wish to shield Mr. Mueller, Congress simply cannot grant Mueller for-cause protection.

Perhaps senators disagree with this constitutional analysis, the views of Justice Scalia, and what I take to be views of Justice Kagan. I enthusiastically endorse the notion that the Senate need not slavishly adhere to whatever the Supreme Court has said about the Constitution. The Senate has a right to reach it its own constitutional conclusions. It is the constitutional inferior of no one, not even the Supreme Court.

But debating this bill at the tail end of the 115th Congress, with the press of other pending business, is a recipe for a constitutional disaster. The constitutional issues deserve plenty of floor time, something the Senate can ill-afford right now. I tell my kids not to cram for exams and I would counsel the Senate not to conduct a clipped and cursory constitutional debate in order to take up a hapless bill with no chance of passage.

If, as many suspect, the bill merely represents a desire to signal senatorial alarm with the specter that the executive will oust Mr. Mueller, there is a much better way for the Senate to weigh in. If senators wish to signal their support for the continuance of Mr. Mueller’s investigation, they can pass a sense of the Senate resolution signaling that 50, 60 or 70 senators wish to be on the record opposing any executive attempt to remove Mr. Mueller.

No one doubts that Congress has the constitutional power to opine on how other branches exercise their constitutional and statutory powers. Such resolutions stretch back centuries. In fact, many might suppose that Congress ought to be far more engaged and more frequently give voice to its constitutional views and opinions. I agree that the Senate and the Congress have many constitutional voices worth hearing.

A Senate resolution, however strongly it might be worded, would not need the House’s concurrence. President Trump could not veto it. More importantly, it, unlike any bill granting Robert Mueller for-cause protection, would be fully constitutional.

Sai Prakash is the James Monroe Distinguished Professor of Law at the University of Virginia Law School and senior fellow at the Miller Center. He teaches constitutional law, foreign relations law and presidential powers. He is a graduate of Stanford University and Yale Law School.

The views and opinions expressed in this commentary are those of the author and do not reflect the official position of The Daily Caller.