Rep. Trey Gowdy (R-S.C.) in January. (Mark Wilson/Getty Images)

There's one finding in particular from House Republicans' just-closed Russia inquiry that has critics and legal experts openly questioning the entire investigation's credibility: In their 150-page report, Republicans said they could find no conclusive evidence that Russia interfered in the presidential campaign to help Donald Trump win. That's despite the CIA declaring more than a year ago that Russia actively tried to help him.

Unless Republicans somehow have come across new information in the CIA's intelligence that the agency missed, Democrats and some legal experts say it's more likely Republicans are trying to hand the president a talking point by drawing a big red line favorable to him: Yes, Russia interfered in the campaign, but no, that's not why Trump is president.

So it's notable that the House Intelligence Committee's GOP report just took another credibility hit, this time from within the party's ranks. A key Republican sided with the CIA on Tuesday about Russia's intentions for Trump. In a statement, Rep. Trey Gowdy (S.C.) said it was “clear based on the evidence” that Russia wanted Democratic nominee Hillary Clinton to lose. Russia wanting Clinton to lose is the same thing as wanting Trump to win, a Gowdy aide clarified.

Even though Gowdy said he agrees with the rest of his committee's findings (most notably that there was no evidence of collusion between Trump's campaign and Russia), Gowdy has parted with Republicans on a significant issue. Trump likes to claim Russian interference had nothing to do with his win. Gowdy isn't claiming Russia swayed the election for Trump, but he is saying Russia at least tried. Gowdy also just gave a powerful talking point to Democrats, who say House Republicans' investigation is politically tainted.

Here's why:

1. Gowdy is the only Republican who read the classified surveillance from the CIA on Russia and Trump: Members of Congress don't send their own spies into Moscow to try to uncover the truth. They rely on intelligence gathered from U.S. spies, surveillance and other methods. As House Republicans were writing a memo alleging FBI bias when the bureau got a warrant to spy on former Trump campaign official Carter Page, it was Gowdy who read the secret warrant put together by the FBI. That means Gowdy had access to intelligence material that no other Republican on the committee did, and thus, ostensibly, has more insight into that intelligence.

2. Gowdy is not shy about partisan fights: Gowdy is one of the most aggressive GOP investigators in Congress. He worked side by side with House Intelligence Chairman Devin Nunes (R-Calif.) on that controversial memo, the one the FBI warned the public was cherry-picked to be political. You've probably heard his name in the context of the House investigation of the 2012 terrorist attacks in Benghazi, Libya, that happened when Clinton was secretary of state. Gowdy led an aggressive election-year investigation of the attacks, having Clinton sit for a 11-hour hearing during the presidential campaign and coming out with a report months before Election Day criticizing her for not doing more to protect the four Americans who were killed, including a U.S. ambassador.

3. Gowdy is retiring: Gowdy sits on the House Intelligence Committee, and he's chairman of the House Oversight Committee. He is among the half a dozen chairmen who have announced they won't run for reelection. Since then, Gowdy has been much more open about speaking his mind. “I've been a pretty lousy politician,” he said after announcing his retirement. Freedom from reelection means he can speak his mind on Russia, perhaps in a way other Republicans can't. Which brings us to our final point.

4. He's refusing to hand Trump his biggest wish: Anyone with even a passing knowledge of the ongoing Russia-Trump investigations knows that Trump desperately wants two things to come out of them:

1. To be cleared of collusion with Russia.

2. Not to have his extraordinary election win tainted by questions of whether Russia pushed him over the edge. Intelligence officials have said that although Russia did try to help Trump win, and the influence of its efforts is incalculable, there's no evidence Russia changed any vote after it was cast.

Trump also hasn't been shy about pressing lawmakers and intelligence officials involved in the investigations. The New York Times reported last fall that Trump repeatedly urged Republicans in the Senate to end their Russia inquiry. House Republicans haven't been shy about working with Trump on Russia, either. Nunes had to step down from the Russia investigation over allegations of impropriety after he briefed Trump on wiretapping claims. In that context, it's suspect that House Republicans chose to agree with the president over the CIA, legal experts say.

“This report contradicts the conclusion of the entire intelligence community,” former FBI agent Asha Rangappa said. “That's coming from human sources, signal intelligence, electronic sources. I truly have no idea how they are able to draw that conclusion without having ever seen the things that all these agencies have.”

5. Some of Gowdy's colleagues are backing off their premise now, too: The lead of the Russia investigation, Rep. K. Michael Conaway (R-Tex.), told reporters Tuesday that “it's clear [Russians] were trying to hurt Hillary,” and that “everybody gets to make up their own mind whether they were trying to hurt Hillary, help Trump. It's kind of glass half full, glass half empty.”

For an investigation whose credibility is being called into question, Gowdy is a significant defection.

More reading:

Did House Republicans end their Russia investigation prematurely? 

The FBI just gave us another reason to be skeptical of the GOP memo

Is there a GOP conspiracy to discredit the Russia investigation?