The expected resignation of Republican Senator Ben Sasse, one of a handful of GOP senators who voted to convict former President Donald Trump in his impeachment trial in February 2021, will allow Nebraska's governor to appoint a replacement to fill the seat.

Among the names listed in an initial wave of speculation on Thursday were Nebraska GOP Representatives Mike Flood and Don Bacon, as well as outgoing Governor Pete Ricketts. Under Nebraska law, the state's governor is responsible for filling vacancies in Nebraska's representation in the U.S. Senate.

Geoff Lorenz, an assistant professor of political science at the University of Nebraska-Lincoln, told Newsweek that Ricketts, a Republican who is not seeking reelection because of a term limit, is the most likely person to fill Sasse's seat.

"I'd expect that this would happen after the new governor—who will almost certainly be Republican nominee Jim Pillen, a close Ricketts ally—takes office in January," Lorenz said. 

Pillen won the GOP gubernatorial primary in May this year, beating out a Trump-endorsed candidate, Charles Herbster. Ricketts endorsed Pillen in January in a notable break with Trump and even argued that Herbster wasn't fit for the job. 

"While I agree with President Trump on many things, I strongly disagree that Charles Herbster is qualified to be our next governor," Ricketts said, according to the Associated Press. 

Lorenz said, "The interesting tension here is that while Pillen—again, Ricketts' preferred candidate—won the primary, his much more outwardly Trumpist opponent, Charles Herbster, recently succeeded at taking over the Nebraska Republican Party organization." 

He continued, "This means that there is a direct and quite vicious factional conflict between the [Nebraska] GOP's organizational leaders and activists and some of its most prominent statewide elected officials, including Ricketts, Pillen and Sasse."

In August, Herbster and his team announced a new political action committee aimed at pushing local and state candidates and officeholders more to the right, the Nebraska Examiner reported.

Lorenz said, "Whoever is appointing Sasse's replacement will have to choose whether to pick someone loyal to—or who is, in fact—Ricketts while that window is open, or to pick someone more broadly acceptable to where the party has gone in recent years. There are good reasons for both strategies."

Lorenz said that he wouldn't count on Bacon or Flood being selected to fill the Senate vacancy. This is because Bacon "has had to distance himself from the party somewhat in order to carry his seat," while Flood "is a brand-new member of Congress, and like many new members he has focused on being a loyal party soldier."