Kevin McCarthy was ousted as speaker of the House of Representatives Oct. 3, after eight House Republicans joined with Democrats to remove him from the role in a historic vote, setting the stage for a contentious process to elect a new speaker.

The ouster marked the first such instance in U.S. history and left House Republicans without a clear successor to lead the House Republican majority.

Matthew Green, a professor of politics at The Catholic University of America in Washington who studies Congress, told OSV News that Democrats backed the effort to oust McCarthy not due to meme partisanship or policy disagreements, but because they argued "that he has gone out of his way sometimes to attack them in ways that they find unfair."

"If you think they've been treating you unfairly, it's hard not to take that opportunity," Green said.

McCarthy was elected speaker in January by a narrow Republican majority after 15 rounds of voting and struggled to unify different factions within his party during his brief speakership.

Rep. Matt Gaetz, R-Fla., introduced the motion to vacate the speakership held by McCarthy. Eight Republicans joined all House Democrats in the vote to remove McCarthy. But allies of McCarthy suggested that an investigation by the House Ethics Committee may soon bring cause to expel Gaetz from the conference, including allegations of sexual misconduct and impermissible gifts under House rules.

In a post on X, formerly known as Twitter, McCarthy wrote, "I will not seek to run again for Speaker of the House."

"I may have lost a vote today, but I fought for what I believe in—and I believe in America," he wrote. "It has been an honor to serve."

"I loved every minute," McCarthy told reporters in a press conference about his time as speaker. He said he would not seek the role again and would instruct House Republicans to choose someone else.

In a statement that did not name McCarthy, White House press secretary Karine Jean-Pierre said President Joe Biden "has demonstrated that he is always eager to work with both parties in Congress in good faith on behalf of the American people."

"Because the urgent challenges facing our nation will not wait, he hopes the House will quickly elect a Speaker," Jean-Pierre said. "The American people deserve leadership that puts the issues affecting their lives front and center, as President Biden did today with more historic action to lower prescription drug prices. Once the House has met their responsibility to elect a Speaker, he looks forward to working together with them and with the Senate to address the American peoples' priorities."

After McCarthy's ouster, the House canceled votes for the remainder of the week.

It was not immediately clear who House Republicans may choose to succeed McCarthy. But Catholic University's Green said whoever that may be "is going to have the same challenges that McCarthy did."

"It's a tiny majority with a significant, rebellious, internal faction in a divided government," Green said.

Asked whether House Republicans could constitutionally choose someone who is not a member of the House, Green said, "the Constitution does not say you have to be a member of the House to be speaker."

"That is true. However, legal scholars and constitutional scholars generally agree that the intent of the founders was to have a member of the House be speaker," he said. "So if the house were to elect someone who is not speaker, he would probably be challenged in the courts. I don't know what the result would be. Maybe the courts would uphold that decision. But I would say that it's exceedingly unlikely."