Justice Department Inspector General Michael Horowitz is testifying Wednesday about his findings that the FBI investigation of President Trump’s 2016 campaign featured “serious performance failures” but was not motivated by political bias.

The inspector general’s appearance before the Senate Judiciary Committee comes amid a tense standoff among senior government officials over the 434-page report analyzing the FBI investigation in 2016 to determine if anyone in the Trump campaign was conspiring with Russia to interfere in the presidential election.

“We did not find any documentary or testimonial evidence that political bias or improper motivation influenced the FBI’s decision to conduct these operations,” Horowitz said in his written testimony to the committee. But his report also found failures up and down the chain of command, “including FBI senior officials who were briefed as the investigation progressed.”

Republicans and Democrats have trumpeted the parts of the report that validate their wildly opposing views regarding the nature of the FBI’s investigation, as either a baseless “witch hunt” or a fundamental defense of American democracy.

The committee chairman, Sen. Lindsey O. Graham (R-S.C.), attacked those who emphasized Horowitz’s finding that the FBI had adequate cause to open the Russia case. Such a takeaway, he said, ignores that the inspector general also found serious wrongdoing in how the FBI conducted the investigation, particularly in its applications to a court to surreptitiously monitor former Trump campaign adviser Carter Page.

Graham said he would assume, “for the sake of argument,” the FBI had an adequate basis to open a counterintelligence investigation — though he noted the standard for doing so is low. But the other failures, he said, were more than a few modest mistakes.

“What happened here is not a few irregularities,” Graham said. “What happened here is the system failed. The people at the highest levels of our government took the law into their own hands.”