By contrast, Mr. Tuberville’s petulant demonstration has been going for more than four months. He announced his blockade in mid-February, holding up at least 150 pending promotions for generals and admirals. Since the Pentagon has no intention of changing its policy — which reimburses military personnel for travel to another state for an abortion because many states have banned the procedure — and since the senator has resisted even the pleas of Republicans to back down, the hold now threatens hundreds more promotions. In a few weeks, the Marine Corps is likely to be without a confirmed leader.

“He is effectively accomplishing what our adversaries could only dream of: denying our military of its leadership and degrading our ability to fight and win the nation’s wars,” said Senator Jack Reed, Democrat of Rhode Island, who leads the Armed Services Committee, in a recent floor speech.

Similarly, Mr. Vance must know the Justice Department will never withdraw the indictment of Mr. Trump, so his blockade of the department’s promotions and executive hires could go on indefinitely, no doubt pleasing Mr. Trump and his supporters. Preventing new federal prosecutors from taking their jobs, however, will eventually have a serious effect on the government’s ability to fight federal crimes and should alarm anyone who cares about the rule of law.

Individual senators gain the power to effectively block nominations by dragging out old and tedious Senate rules of procedure that are in desperate need of an update. Usually, the Senate majority leader brings up batches of routine military promotions and gets unanimous consent to approve them. But if a single senator breaks that unanimity, then each promotion has to be brought up one by one; at two or three days per vote, that can take a great deal of time, far more than the Senate has. In each two-year Congress, there are approximately 65,000 military appointments and promotions and 2,000 civilian nominations for the Senate to consider, and if the vast majority are not approved by unanimous consent, many arms of government will cease to function.

The hold is a cousin of other undemocratic privileges in the Senate, like the blue slip process, which allows home-state senators to block nominations for federal judges, or the filibuster, which raises the threshold for passage of most legislation to 60 votes. Brian Fallon, a former aide to the majority leader, Chuck Schumer, said those kinds of privileges are artifacts of a racist past, used by white Southern senators to prevent passage of civil rights legislation or nominations that might have interfered with their way of life. But lately they are being taken to new heights by the MAGA wing of the Republican Party.