House Oversight Committee Chairman Trey Gowdy tore into FBI official Peter Strzok at the opening of Thursday’s high-profile hearing with the anti-Trump former investigator, saying he showed “textbook bias” on the job. 

Gowdy and House Judiciary Committee Chairman Bob Goodlatte both rattled off a slew of Strzok text messages in which he blasted then-candidate Donald Trump and pined for a Hillary Clinton victory in 2016. 

As Strzok observed opening statements from the witness table, Gowdy expressed disbelief that he didn’t view such statements as bias. 

In Strzok’s first public hearing, Goodlatte also challenged Democrats to replace Trump’s name in those texts with their own. 

“To my colleagues on the other side of the aisle, please replace President Trump’s name with your own name in a small sample of things Mr. Strzok has said,” Goodlatte said. “Envision how you would feel if you found out that the chief agent investigating you as a Member of Congress was making these comments: ‘F Trump,’ ‘Trump is a disaster,’ ‘Just went to a southern Virginia Walmart.  I could SMELL the Trump support’ – or, perhaps most alarmingly and revealingly, ‘We’ll stop it’ – referring directly to Mr. Trump’s candidacy for President.”

Goodlatte challenged Democrats who “disparage” the investigation as a “mere conspiracy theory” to imagine they were under investigation.

Democrats, in opening statements, blasted their GOP colleagues. Rep. Elijah Cummings highlighted that several Trump-tied figures have already been snagged in the Russia probe. 

“These are not allegations, these are admissions,” he said. 

Strzok has been in political crosshairs for months over revelations of anti-Trump text messages exchanged with his lover, and former bureau colleague, Lisa Page.

Strzok said in his prepared opening statement that he has never allowed personal opinions to affect his work, that he knew information during the campaign that had the potential to damage then-candidate Trump but never contemplated leaking it to the press, and that recent congressional focus on him is misguided and plays into “our enemies’ campaign to tear America apart.”

Strzok’s messages were first revealed by Justice Department Inspector General Michael Horowitz. The latest text, which was revealed in the inspector general’s report on the FBI’s handling of the Clinton email investigation, showed Strzok vowing to “stop” Trump from becoming president.

GOP leaders are expected to grill Strzok over the slew of Trump-bashing texts he exchanged on his FBI phone while he worked on bureau investigations into Russian election meddling and Hillary Clinton’s email sever. Lawmakers are also expected to press Strzok on the impact of his political bias on any investigative decisions, though Horowitz ultimately found that despite the politically charged messages, there was no evidence that the bias had an impact on any prosecutorial decisions in the Clinton probe.

Strzok was on Special Counsel Robert Mueller’s team until the text messages were discovered. He was then reassigned to the FBI’s office of human resources. Just last month, Strzok was escorted from the bureau and lost his security clearance.

In his opening statement though, Strzok maintained that while his criticisms of Trump were “blunt,” there is “simply no evidence of bias in my professional actions.”

“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,” Strzok said adding that Russian election interference has been successfully “sowing discord in our nation and shaking faith in our institutions.”

“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,” Strzok said. “As someone who loves this country and cherishes its ideals, it is profoundly painful to watch and even worse to play a part in.”

Strzok also rejected President Trump’s characterization of the Mueller probe as a “witch hunt.”

“This investigation is not politically motivated, it is not a witch hunt, it is not a hoax,” Strzok said.

Strzok’s public testimony comes after his appearance on Capitol Hill last month, when he interviewed with the committees behind closed doors for more than 11 hours. Lawmakers on Thursday are expected to question Strzok on why he did not act immediately when potentially classified emails were found on a laptop belonging to disgraced former Rep. Anthony Weiner, who was married at the time to top Clinton aide Huma Abedin.

Strzok was romantically involved with Page, who resigned from the bureau in May. Page also served on brief detail for Mueller, but returned to the FBI last July where she served in the Office of General Counsel.

This week, Page defied a congressionally issued subpoena to appear Wednesday for a closed-door deposition before the same committees. Page’s legal team, late Tuesday night, said she would not testify because she needed more time to prepare.

House Republicans sent a letter to Page’s attorney on Wednesday, laying out three options for Page: show up at Thursday’s public hearing alongside Strzok, attend a closed-door deposition on Friday or face contempt of Congress proceedings beginning Friday morning.

House Judiciary Committee Chairman Bob Goodlatte, R-Va., said Thursday morning that Page, through her attorney, has agreed to appear for a private interview on Friday, voluntarily. 

“The good news is that late last night, through her attorney, Lisa Page did agree to appear for a private interview on Friday, voluntarily,” Goodlatte said on Fox Business’ “Mornings with Maria.” “We are still working out details.” 

Trump, from his European tour, blasted Page for failing to show up on Wednesday, calling the ongoing Russia probe “perhaps the most tainted and corrupt case EVER!”

He added: “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? Read his hate filled and totally biased Emails and the answer is clear!”

Fox News’ Gregg Re and Pamela K. Browne and The Associated Press contributed to this report.