That threat contained the rumblings of institutional conflict between Congress and the executive branch. The recent practice of Congress in the face of presidential power has been to resort to judicial cover. After Mr. Obama unilaterally delayed implementation of the employer mandate under the Affordable Care Act in 2013, the House of Representatives, then under Republican control, voted to sue him for exceeding his constitutional powers. In the current dispute, Mr. Schiff also warned that he might take the administration to court.

But this is asking another branch to do Congress’s work when the legislature could instead flex its own institutional muscle, what the conservative constitutional scholar Richard M. Reinsch II has called “ bodycheck constitutionalism.” No such muscle is stronger than Congress’s power over appropriations. What may seem like picayune politics — depriving Mr. Maguire’s office of funds — is in fact precisely what the Constitution contemplates as one of the foremost means of asserting Congressional authority.

This power of the purse, which assumes particular urgency in light of Congressional abdication of its authority to the executive, has generally been seen as a tool of policy. But the appropriations power is equally important as a means of enforcing Congressional will on procedural matters like compliance with oversight. Mr. Schiff’s threat to deprive Mr. Maguire’s office of funds signals a revival of institutional conflict to maintain the separation of powers.

That is not to say that starving one office will bring the imperial presidency down. But the combination of these Congressional responses has already forced Mr. Trump to deliver the whistle-blower complaint to Capitol Hill. Mr. Maguire is set to testify before Congress on Thursday.

It would be even more significant for the imperial presidency if these events are a prelude to escalating institutional conflict under this and future administrations. The original constitutional design anticipates that struggle, assuming that the elected branches of government will use their authorities to defend themselves.

James Madison wrote about this institutional self-defense in Federalist 51. One of the essay’s most famous lines reads, “Ambition must be made to counteract ambition.” The key to understanding how ambition maintains the separation of powers comes shortly before that, though:

But the great security against a gradual concentration of the several powers in the same department, consists in giving to those who administer each department, the necessary constitutional means, and personal motives, to resist encroachments of the others.

Congress has long had the means to resist the presidency. It now appears to be reviving a desire to use them.

There are legitimate criticisms of the dangerous practice of executive branch officials disclosing the details of private presidential conversations with other heads of state. But such questions should be answered by a clash between branches ultimately superintended by the people, to whom the president can also appeal.