President Trump in the White House on April 9. (Oliver Contreras/For The Washington Post)

“THERE IS no reason to go any further, and especially in Congress,” President Trump told Post reporters Tuesday, explaining why he was preparing to stonewall congressional requests for administration documents and testimony, possibly by invoking executive privilege. “We’re fighting all the subpoenas,” Trump said on Wednesday. “These aren’t like impartial people.”

If that were the standard, then Congress could never investigate anything. Mr. Trump’s Republican colleagues must remember the battles they fought with President Barack Obama over transparency only a few years ago when they ran the House. Mr. Obama asserted executive privilege to prevent then-Attorney General Eric H. Holder Jr. from turning over documents on the “Fast and Furious” gun-running scheme. Republicans held Mr. Holder in contempt of Congress.

As we said at the time, “No doubt a lot of congressional investigations are partisan fishing expeditions. For better or worse, that comes with the democratic territory. Absent very strong countervailing considerations — stronger than some of those the administration has asserted in this case — Congress is generally entitled to disclosure.” Democrats, too, are entitled to disclosure, particularly as they ask weighty questions about the potentially severe abuse of power in the top reaches of the White House.

Mr. Trump’s own words reveal that he is motivated not by any specific concern about protecting presidential decision-making or some other crucial executive-branch function — but by concealing anything that might land him in political jeopardy. Courts have said little on the limits of executive privilege, but judges have been skeptical that the president has a generalized interest in secrecy that outweighs legitimate investigative inquiries. Given Mr. Trump himself admits that much of the information his aides might disclose has already been revealed in special counsel Robert S. Mueller III’s investigation, the president appears mostly interested in avoiding a public spectacle. That is not the purpose of executive privilege.

Even so, administration officials say they will fight a congressional subpoena of former White House counsel Donald McGahn, whose testimony to Mr. Mueller proved damning for the president in the special counsel’s report. Mr. McGahn insisted that Mr. Trump told him to fire Mr. Mueller. The former White House counsel also said the president told him to deny that the episode ever occurred after reporters publicized that Mr. Trump had tried to meddle in an investigation into his own possible obstruction of justice. This episode could easily form the basis of an impeachment inquiry; it is well within the House Judiciary Committee’s right to insist on conducting its own follow-up questioning after the Mueller report’s release.

The story is similar on the House Oversight Committee’s desire to question a White House official involved in issuing security clearances, allegedly to people who should not have them. It is in the public’s interest for lawmakers to determine whether administration officials cut corners to hand out security clearances, possibly endangering national security.

In the past, the executive branch and Congress generally struck deals to avoid direct confrontations on executive secrecy. But Mr. Trump seems unlikely to ditch his pugnacious attitude. If and when courts consider the situation, they will find a president unreasonably hostile to Congress’s legitimate interest in gathering information.