Rep. Trey Gowdy (R-S.C.) has spent the better part of the past 15 hours poking holes in President Trump's dubious trial balloon about a spy in his campaign.

Gowdy, who was one of the few people to get briefed on the situation last week, told Fox News on Tuesday night that the briefing vindicated the FBI: “I am even more convinced that the FBI did exactly what my fellow citizens would want them to do when they got the information they got, and that it has nothing to do with Donald Trump.”

Then Wednesday morning on CBS, Gowdy, a former U.S. attorney who is retiring from Congress this year, rebuked Trump's use of the term “spying” to describe his law enforcement colleagues. " 'Undercover,' 'informant,' 'confidential informant' — those are all words I'm familiar with,” Gowdy said. “I've never heard the term 'spy' used.”

The comments are certainly the strongest GOP counterpoint to Trump's narrative to date, and they fill out a familiar pattern: Trump saying something baseless, almost no Republicans of any real stature vouching for him, and a few brave souls stepping forward to debunk him — likely in vain.

Gowdy's fellow South Carolina Republican, Sen. Lindsey O. Graham, has also dipped his toe into this controversy — albeit more hesitantly. He told Hugh Hewitt last week that Trump should “probably not” call what the FBI did spying and said “a confidential informant is not a spy.” Sen. Marco Rubio (R-Fla.) likewise tried to thread the needle, saying Sunday there was “no evidence” the FBI did anything wrong here.

Those are three pretty high-profile rebukes from fellow Republicans of the entire basis for Trump's claim, and we really haven't seen the inverse: Republicans lending credence to Trump's theory. Some have said we should make sure there weren't any abuses, sure, but that's a pretty bland, noncommittal comment, and it doesn't exactly suggest Trump has uncovered something real. It doesn't speak to his evidence. Even House Intelligence Committee Chairman Devin Nunes (R-Calif.), Trump's most important ally in the House, has been quiet since receiving the briefing alongside Gowdy. That, perhaps more than anything, speaks volumes.

But we've been here before, and the lack of any real backup for Trump's claims hasn't stopped the GOP base from buying into them. Few top Republican members of Congress are calling the Russia investigation a “witch hunt,” as Trump has, yet 82 percent of Republican voters and 44 percent of all Americans believe it is. The Nunes memo that alleged a political and abusive predicate for the Russia probe wasn't exactly embraced by Republicans, but it has  contributed to Trump's narrative. GOP members were as circumspect about Trump's baseless claim that President Obama wiretapped his campaign as they are about this “spying” narrative, but polling showed three-quarters of Republicans bought into it. Polling has also shown that the vast majority of Republicans believe the FBI is working to delegitimize Trump — a narrative that has been pushed using dubious readings of then-FBI agent Peter Strzok's text messages and other tools.

Almost none of these conspiracy theories have been embraced by the broader, official Republican Party. Almost all of them have broken through, thanks to Trump's singularity, his saturation of media coverage and the lack of a concerted pushback beyond people like Gowdy, Graham and Rubio — who have routinely paid a political price for running afoul of Trump.

Gowdy is not seeking reelection after this term, so he does not have to worry about the political consequences of speaking out against Trump.

At this point in the GOP, silence is essentially confirmation, and opposition is apostasy. Gowdy decided he wouldn't be silent, but he's likely to find himself pretty lonely.