Veteran FBI agent Peter Strzok on Thursday rejected accusations of anti-Trump bias in his work on the Russia collusion probe, telling lawmakers in a tempestuous hearing that attacks on the FBI and Justice Department were a "victory" for Vladimir Putin.
Strzok told lawmakers that his comments in private text messages to his lover, FBI lawyer Lisa Page, were a reaction to Donald Trump's "horrible, disgusting behavior" on the 2016 campaign trail.
But he denied that his personal political leanings had colored his professional judgment, as Republicans raised doubts about the integrity of Special Counsel Robert Mueller's investigation into ties between Trump's election campaign and Russia.
"This investigation is not politically motivated, it is not a witch hunt, it is not a hoax," Strzok told the House Judiciary and Oversight Committees.
"I have the utmost respect for Congress's oversight role, but I truly believe that today's hearing is just another victory notch in Putin's belt, and another milestone in our enemies' campaign to tear America apart."
- Accused of pursuing Trump's impeachment -
The eight-plus hour hearing resembled a brawl between Democrats and Republicans much of the time, coming as Mueller's investigation into possible collusion and obstruction increasingly menaces the White House and Trump himself.
Republicans have seized on Strzok and Page's tens of thousands of text messages over 2015-2017 -- when both were involved in the Russia investigation -- as proof that the FBI is too riddled with bias to fairly investigate Trump.
Leading Republican attacker Trey Gowdy cited Strzok's May 2017 texts speculating that the newly launched Mueller probe could lead to Trump's impeachment as proof that it was politically tainted from the start.
"You as a counterintelligence officer had no interest in participating in a counterintelligence investigation that was not going to lead to impeachment," Gowdy told Strzok.
"A bias-free investigation is not a Republican or Democrat issue -- it's an American issue," he said.
Strzok denied the accusation. "I did not know what existed. I had prejudged nothing," he told the panel.
Gowdy also latched onto Strzok's August 2016 text to Page -- just after the start of the initial FBI probe into links between the Trump campaign and Russia -- promising that the real estate mogul would not become president.
"No. No he won't. We'll stop it," Strzok told her.
Strzok said the comment was a response to Trump's recent actions on the campaign trail.
"You need to understand that that was written late at night off the cuff, and it was a response to a series of events that included then-candidate Trump insulting the immigrant family of a fallen war hero," Strzok told the panel, sparking a burst of applause from the audience.
It reflected, he said, "my presumption, based on that horrible, disgusting behavior, that the American population would not elect someone demonstrating that behavior to be president of the United States."
- 'FBI lovers' -
Trump has dubbed Strzok and Page the "FBI lovers" in a series of tweets in which he also labels the Mueller investigation a "witch hunt."
"How can the Rigged Witch Hunt proceed when it was started, influenced and worked on, for an extended period of time, by former FBI Agent/Lover Peter Strzok?" Trump tweeted ahead of Thursday's hearing.
"Read his hate filled and totally biased Emails and the answer is clear!"
Strzok said he was embarrassed by the texts, but that they did not represent his or the FBI's work ethic.
"Like many people, I had and expressed personal political opinions during an extraordinary presidential election... opinions that were not always expressed in terms I am proud of," he said.
"But let me be clear, unequivocally and under oath: not once in my 26 years of defending my nation did my personal opinions impact any official action I took."
Democrats during the hearing struggled to head off the attack and focus the attention on the broader issue of Russian election meddling and possible collusion.
Representative David Cicilline told Strzok he is being used as "a prop, so they can promote an narrative in an ongoing effort to distract from the serious investigation by the special counsel that is closing in on the Trump inner circle."
"It's not about you, it's about protecting the president," he said.