Peter Strzok, a veteran FBI counterintelligence official deeply involved in the Russian Federation investigation of Trump's campaign, insisted he was impartial despite his controversial August 2016 text exchange with ex-FBI lawyer Lisa Page, with whom he was then having an affair.
"I don't give a damn what you appreciate, agent Strzok".
It is point that has been largely brushed aside in Trump-friendly media circles, with a text Strzok sent to Page in May 2017 also receiving comparatively little scrutiny.
The two agents disparaged Trump throughout 2016, describing him as an "idiot" and a "menace".
Strzok repeatedly insisted that the texts, including one in which he called Trump a "disaster", did not reflect political bias and had never infected his work.
"Agent Strzok had Hillary Clinton winning the White House before he finished investigating her", said Rep. Trey Gowdy, Republican chairman of the House Oversight and Government Reform Committee. In it, Strzok describes his reluctance to work on behalf of the special counsel, and that seemed to imply he didn't think there would be substantial findings of collusion between Russian Federation and the Trump campaign team.
Although the president had just concluded a long day of meetings at the North Atlantic Treaty Organisation summit in Brussels, his mind was clearly on Washington, as he tweeted about the "Rigged Witch Hunt" and Mr Strzok's "hate filled and totally biased Emails" just before 1am local time. "It is not a hoax".
In one particularly testy exchange, Trey Gowdy of SC questioned Mr Strzok about messages in which he said "we'll stop" Mr Trump's election and that Democrat Hillary Clinton should win 100m votes to zero.
Page had been subpoenaed to appear on Capitol Hill on Thursday, but did not comply with the order because Congress hadn't given her "sufficient time to prepare".
Republicans eager for ways to discredit Mueller's investigation have for months held up the texts from Strzok and Page to support allegations of anti-Trump bias within federal law enforcement.
Democrats, meanwhile, slammed the Republicans for their attacks on Strzok as an effort to undermine the Mueller investigation.More news: Trump blasts May over Brexit during United Kingdom visit, casting pall over ties
"I know they're having a lot of problems and their economy is collapsing".
But Republicans lambasted the embattled FBI agent, accusing him of "textbook bias" in his handling of the Clinton and Trump investigations.
Rep. Jim Jordan (R-Ohio) explained the pivotal piece of the puzzle about the origins of the Russian investigation that was revealed by Peter Strzok in his testimony before Congress Thursday. "Agent Strzok may not see it, but the rest of the country does".
"They would not tolerate any improper behavior in me anymore than I would tolerate it in them", Strzok said. He told Gohmert the fact that he would say that to him "shows more what you stand for" than anything else.
Rep. Bob Goodlatte (R-Va.), the chairman of the House Judiciary Committee, threatened Strzok with contempt, claiming he was under subpoena.
Cuomo broke out his whiteboard to detail why he thinks House Republicans failed to make their case against Strzok and their ultimate target, Mueller.
Strzok replied that Trump won't. New Jersey Democratic Rep. Bonnie Watson Coleman said, "You need your medication!"
He said bias means that you let those opinions get in the way of the work, and he did not do that.
"Not at all", a defiant Strzok said.
California GOP Rep. Darrell Issa of California took the step of asking Strzok to read his own text messages out loud at the hearing, including when he called Trump a "douche".
In his opening statement, Strzok acknowledged that while his text message criticism was "blunt", it wasn't directed at one person or party and included jabs not only at Trump but also at Clinton and Sen.