A House committee held an impeachment hearing Tuesday on IRS Commissioner John Koskinen, examining allegations that he misled and lied to Congress during investigations into the targeting of conservative groups seeking tax-exempt status.

Republicans have long argued that Koskinen obfuscated during congressional inquiries and misled lawmakers regarding the extra scrutiny conservative groups received from the IRS. Democrats have countered that the uproar is partisan in nature and that while there may have been incompetence at the IRS, multiple investigations have shown no wrongdoing by the commissioner.

Tuesday’s hearing, the first of two the House Judiciary Committee will hold on the possible impeachment of Koskinen, featured testimony from two Republican members of Congress: Oversight Committee Chairman Jason Chaffetz and Florida Rep. Ron DeSantis, the chairman of an oversight subcommittee. Chaffetz introduced (and DeSantis co-sponsored) a resolution to impeach Koskinen last October.

The hearing quickly devolved into a partisan fight during the opening statements. Koskinen declined to testify before the committee, citing not enough time to prepare because he had been abroad and received only a one-week notice of the hearing.

Rep. John Conyers Jr., the top Democrat on the Judiciary Committee, attempted to introduce written testimony from Koskinen into the record, but Rep. Darrell Issa, who was chairman of the oversight committee when it began investigating the IRS scandal, blocked that move. Issa argued that if Koskinen wanted to defend himself for the record, he should have appeared before the committee under oath rather than just providing written testimony.

“The witness was invited to come and has delivered us instead a self-serving, written statement,” Issa said. “While telling us in that statement he respects the committee, he’s refusing to be here for his own impeachment inquiry. On what basis would we allow unsworn testimony for what should have been a sworn witness under the penalty of perjury?”

That moment set the tone for the rest of the hearing. Chaffetz, in his opening statement, argued that Koskinen allowed thousands of emails from Lois Lerner, the IRS employee at the heart of the targeting scandal, to be destroyed and didn’t notify lawmakers investigating the incident in a timely manner that those records had been destroyed. He also argued that the IRS, under Koskinen’s leadership, didn’t appropriately search for backups of the missing records, and that Koskinen gave testimony to House investigators that was either willfully or negligently inaccurate and misleading.

“As members of Congress we have no reason to have any confidence that Mr. Koskinen will run one of the most powerful agencies with any integrity,” Chaffetz said in his prepared remarks. “Nor can the American people feel confident the agency won’t misuse its power under his direction. For these reasons, it is time for Congress to act and remove him as head of the agency.”

Conyers, previewing the Democratic arguments on the other side, said there should not be a rush to judgment for a short-term political gain, and that the House should prove any allegations beyond a reasonable doubt before moving to impeach someone.

“This resolution fails by every measure,” Conyers said. “It arises from the worst partisan instincts. It is not based in the facts. And it has virtually no chance of success in the Senate.”

To actually remove Koskinen from office, the House would have to pass a resolution impeaching him on the House floor, and two-thirds of the Senate would have to vote to convict him. Orrin Hatch, chairman of the Senate Finance Committee, said he didn’t view Koskinen’s actions as “an impeachable offense,” according to The Hill. If Koskinen were impeached, this would be the first time the House impeached someone at his level since the 1870s, according to the New York Times.

Chaffetz said after the hearing that the standard of proof for impeachment is different than on a criminal matter, and that there does not necessarily need to be intent behind Koskinen’s actions. Chaffetz said he hopes there will be a mark-up or vote for his resolution against Koskinen sometime in the near future.

“His non-attendance today I think speaks volumes,” he said. “He can’t answer these questions. They are matters of fact and they are indefensible.”

The Judiciary Committee will hold a second hearing in June with outside experts to discuss whether further congressional action is warranted.