Donald Trump Jr.’s shifting explanation of an undisclosed preelection meeting with a Russian lawyer who he was told had incriminating information on Hillary Clinton is rankling lawmakers already struggling to pass any part of President Trump’s agenda.

Rep. Trey Gowdy, R-S.C., said on Fox News Tuesday night that he is troubled by “the amnesia of people that are in the Trump orbit.”

“Here we are beginning another week, this one in July, with a new revelation about Russia,” Gowdy said. “Someone close to the president needs to get everyone connected with that campaign in a room and say: From the time you saw ‘Doctor Zhivago’ until the moment you drank vodka with a guy named Boris, you list every single one of those, and we are going to turn them over to the special counsel. Because this drip, drip, drip is undermining the credibility of this administration.”

Gowdy — who led a two-year congressional investigation into Clinton’s handling of the deadly 2012 attacks in Benghazi, Libya — recently took over for outgoing Rep. Jason Chaffetz, R-Utah, as chairman of the House Oversight and Government Reform Committee.

The committee is set to investigate Trump’s firing of FBI Director James Comey in the middle of the bureau’s investigation into Russian interference in the 2016 U.S. presidential election and the Trump campaign’s possible ties to Russia. (Gowdy already sits on the House Permanent Select Committee on Intelligence, which is conducting its own Russia probe.)

His comments come amid a growing firestorm over emails showing that Trump Jr. took the June 9, 2016, meeting at Trump Tower with Natalia Veselnitskaya, a lawyer with alleged ties to the Kremlin and its spy agency. Trump Jr., campaign chief Paul Manafort and top adviser and Trump son-in-law Jared Kushner also attended the meeting, which was brokered by Robert Goldstone, a music publicist who had previously helped ink a business deal between President Trump and a Russian oligarch close to Vladimir Putin.

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Related: Trump Jr.’s meeting with Russian lawyer: A timeline

In his initial email to Trump Jr., Goldstone claimed a “Russian government lawyer” had “very high level and sensitive information” that was part of the Russian government’s support for the elder Trump’s candidacy.

“Thanks Rob, I appreciate that,” Trump Jr. replied. “If it’s what you say I love it, especially later in the summer.”

Trump Jr. posted the emails on his Twitter feed Tuesday morning after the New York Times had informed him they were set to publish them.

In an interview with Fox News’ Sean Hannity, Trump Jr. said that in retrospect, he would have “probably done things a little differently” in setting up the sit-down with Veselnitskaya.

“Again, this is before the Russia mania, this is before they were building this up in the press,” Trump Jr. told Hannity. “For me this was opposition research, they had something, you know, maybe concrete evidence to all the stories I’d been hearing about, probably underreported for years, not just during the campaign, so I think I wanted to hear it out. But really it went nowhere, and it was apparent that wasn’t what the meeting was about.”

Trump Jr. was asked if he ever had other undisclosed meetings with Russians.

“I’ve probably met with other people from Russia, but certainly not in the context of actual formalized meetings or anything,” the president’s son replied, adding that he was still willing to testify about his dealings with Russia under oath.

In a tweet Wednesday morning, President Trump said his son did “a good job” defending himself on Hannity’s show.

“He was open, transparent and innocent,” Trump tweeted. “This is the greatest Witch Hunt in political history. Sad!”

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