Sen. Ben Sasse (R-Nebraska) speaks during Supreme Court Justice nominee Amy Coney Barrett's confirmation hearing on October 12, 2020.
CNN  — 

Sen. Ben Sasse, a Republican who voted to impeach former President Donald Trump after the attack on the US Capitol, officially resigned from the Senate Sunday, with officials expecting his seat to be filled as soon as this week.

Nebraska’s Republican Gov. Jim Pillen, who was sworn in last week, is likely to appoint Sasse’s replacement in the coming days, officials say. He has assured officials the appointment will be made well before the Senate returns January 23.

Sasse announced last year that he would step down from his position to become the University of Florida’s next president. The university’s Presidential Search Committee recommended him as the sole finalist for the role in October and the Board of Trustees approved his nomination a month later despite criticism from students and faculty over the secretive search process, Sasse’s limited relevant experience and his past criticisms of same-sex marriage.

“I’m here rather than at some other school, or rather than trying to claw to stay in the United States Senate for decades, because I believe that this is the most interesting institution in the state that has the most happening right now, and is therefore the best positioned to help lead our country through a time of unprecedented change,” Sasse told the UF board at the time.

Sasse made little secret of the frustration he felt with the Senate and the changing nature of the Republican Party. He explained his decision to vote to convict Trump by saying that the former president’s lies about the election “had consequences” and brought the country “dangerously close to a bloody constitutional crisis.” He was one of seven Republican senators to vote to convict Trump after the House of Representatives impeached him for incitement of an insurrection.

ben sasse
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02:01 - Source: CNN

Before his election to the Senate in 2014, Sasse was president of Midland University, a private Lutheran liberal arts school in Nebraska with an enrollment of about 1,600 students. He graduated from Harvard and earned a PhD in American history at Yale and also worked at Boston Consulting Group, McKinsey and private equity firms, according to his website.

The University of Florida has an enrollment of over 60,000 students on a 2,000-acre campus with over a thousand buildings. Unlike Sasse, the university’s most recent presidents had extensive careers as administrators at major universities prior to taking the school’s top job.

Sasse was reelected to another six-year term in 2020. His resignation will not change the balance of power in the Senate.

Former Republican Gov. Pete Ricketts, who left office last week after serving two terms, is seen as the leading candidate for the job. Ricketts has long had his eye on a Senate seat, losing a campaign in 2006 to Sen. Ben Nelson, the last Democrat to win a statewide contest in Nebraska.

CORRECTION: This story has been updated to reflect the process by which Ben Sasse became the incoming University of Florida president.

This story has been updated with additional information.