For the first time in a public forum, FBI counterintelligence agent Peter Strzok delivered an impassioned defense against claims from House Republicans that he held biases against candidate Donald Trump that affected his official agency decisions as he helped lead an investigation into ties between the 2016 Trump campaign and Russia.

“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 testified before a joint panel of the House Judiciary and Oversight and Government Reform Committees.

At the heart of GOP lawmakers’ complaints are a series of texts from August 8, 2016, between Strzok and his alleged mistress, Department of Justice lawyer Lisa Page, in which Strzok wrote to Page, “We’ll stop” a Trump presidency.

The hearing commenced roughly 20 minutes late, but when it did, it started with a bang.

Oversight Chairman Trey Gowdy, a former federal prosecutor well-known for his interrogative theatrics at committee hearings, punctuated a particularly heated exchange after Strzok said he did not appreciate Gowdy’s characterization of some of his comments.