President Trump. (Jabin Botsford/The Washington Post)

TO GAUGE the corrosive effects of Trumpism, do not look only at how the president demeans his office daily. (This week’s exhibits so far: bellicose tweets against Iran and spiteful threats to revoke security clearances of his critics.) Look also at how, from some combination of fear, coercion and willing appeasement, members of President Trump’s party who should know better debase themselves — and degrade Americans’ faith in their system of justice — in service of his petty whims.

The Justice Department on Saturday released the warrant applications that investigators submitted to the Foreign Intelligence Surveillance Court asking for permission to surveil former Trump adviser Carter Page. Mr. Trump and his enablers have made the documents central to their claims of FBI bias in its conduct of the Russia probe. In fact, the documents show that the investigative process was sound and the Republican narrative is paranoid, cynical or both.

Participating in the degradation on Sunday was House Judiciary Committee Chairman Bob Goodlatte (R-Va.), who insisted that “there is a serious problem with the FBI” presenting a warrant application that, he claimed, was based on the so-called Steele dossier, a collection of mostly unverified reports about the behavior of Mr. Trump and his associates. As he echoed this line, Sen. Lindsey O. Graham (R-S.C.) said “the warrant, the FISA warrant process needs to be looked at closely by Congress.”

Mr. Goodlatte is a key overseer of the nation’s legal affairs. Mr. Graham served in the U.S. Air Force JAG Corps. Both should know better than to assist in the trashing of a legitimate federal law enforcement operation.

The facts support a different Republican’s take: “You have an individual here who has openly bragged about his ties to Russia,” Sen. Marco Rubio (R-Fla.) said of Mr. Page. “And the FBI’s job is to protect this country from threats. . . . So they look at all this information. They say: We have a guy here who’s always in Russia, brags about Russia, and we have reason to believe — and they list those reasons — why this is someone we should be watching. And they followed the legal process by which to do so.”

The documents show that federal investigators relied at least in part on the Steele dossier, but they also clearly informed the judges that the dossier came from a politically motivated source. As it happened, the dossier’s information on Mr. Page turned out to be more credible than some of its other claims. The documents also contained other information on Mr. Page’s connections to Russia. Moreover, as The Post’s Philip Bump noted, the redacted sections that appear to contain sensitive information on Mr. Page’s activities grew larger with every renewal application.

The documents were compelling enough to persuade judges to authorize the surveillance and renew it three times. This is not surprising: Judges routinely grant warrants on the basis of preliminary evidence. If they did not, law enforcement officials would have an impossible time gathering proof of wrongdoing in cases large and small. You would think Republicans would not want to hamstring law enforcement.

But, as in classic McCarthyism, the number of their targets is expanding even as any evidence of official wrongdoing melts away. On Sunday, Mr. Trump broadcast calls to scrutinize the judges involved. How many Republicans will continue to abet this wanton attack on the Justice Department and the judiciary — on American democracy?