Senate Republicans will be forced to seat Judge Roy Moore if he wins a special election next month to fill Alabama’s U.S. Senate seat, but if he wins, he would likely face a quick expulsion vote that will end his Senate career before it begins.

Republicans began signaling last week they don’t want Moore in the Senate, and that sentiment picked up steam on Monday after a woman stepped forward and claimed Moore sexually assaulted her in his car when she was 16. Beverly Young Nelson said after she resisted, Moore either pushed her out of his car or she fell to the ground as Moore sped away.

A few ideas surfaced over the weekend about how Republicans might be able to deny Moore his Senate seat, but Cory Gardner, R-Colo., who chairs the National Republican Senatorial Committee, outlined the most likely path forward: expulsion.

“I believe the individuals speaking out against Roy Moore spoke with courage and truth, proving he is unfit to serve in the United States Senate and he should not run for office," Gardner said. "If he refuses to withdraw and wins, the Senate should vote to expel him, because he does not meet the ethical and moral requirements of the United States Senate."

Sen. Lindsey Graham, R-S.C., also hinted he's prepared to pull the plug on Moore's Senate career by expelling him, should he win.

“In light of the most recent allegations and the cumulative effect of others, I believe #RoyMoore would be doing himself, the state, the GOP, and the country a service by stepping aside,” Graham tweeted Monday. “If he continues this will not end well for Mr. Moore.”

Legal experts agree that expulsion may be the only way for Congress to rid itself of Moore, who, under the Constitution, is entitled to take his seat if he prevails against Democrat Doug Jones on Dec. 12.

“If he wins the election on the 12th, they are going to have to seat him,” Ronald J. Krotoszynski Jr. a law professor at the University of Alabama, told the Washington Examiner.

The Senate has expelled only fifteen lawmakers since 1789. All but one were expelled for backing the Confederacy during the Civil War.

But the Supreme Court ruled decades ago that lawmakers must swear in a duly elected member or senator if they meet the requirements outlined in the Constitution regarding age, citizenship, and residence. Lawmakers in recent years have challenged this, but haven’t gotten very far.

Senate Majority Leader Harry Reid, R-Nev., briefly delayed swearing-in Sen. Roland Burris in 2009 because the Democrat had been appointed by Gov. Rod Blagojevich to fill the seat, which had been vacated by former President Barack Obama.

Blagojevich had at the time been arrested and charged with corruption and Democrats urged him to refrain from appointing a senator, which he ignored. Democrats eventually relented and let Burris take the seat.

“There is a precedent for delay, but denial is not an option,” Krotoszynski said.

If forced to seat Moore, the next step would be finding a two-thirds majority in favor of expelling him, which on Monday didn't seem like a very hard threshold to meet. Senate Majority Leader Mitch McConnell, R-Ky., said Moore should drop out, and the No. 2 Republican in the Senate, withdrew his endorsement of Moore.

Other ideas floated over the past few days seem far less likely.

On Monday, White House officials suggested that Alabama Gov. Kay Ivey might block Moore from taking the seat if he wins, and then appoint Attorney General Jeff Sessions, who held the seat until just a few months ago. But the courts have generally found over the years that states cannot interfere with the terms of elected members of the House and Senate.

Additionally, Sessions signaled he’s not interested in returning to the Senate, where he served for two decades.

Most seemed resigned to the idea that Moore, who was clearly leading his Democratic challenger before last week's sexual assault revelations were made public, may have to temporarily hold a Senate seat if he wins.

On Sunday, Sen. Amy Klobuchar, D-Minn., acknowledged on "Meet the Press" that the Senate “may not have much of a choice,” on seating Moore, but said the Senate can expel him after an Ethics Committee investigation.

“That’s one way we could do it,” Klobuchar said.

Meanwhile, Republican leaders said Monday they are hoping to stop Moore from ever reaching the Senate. Majority Leader Mitch McConnell said the party is weighing a possible write-in candidacy for another Republican candidate.

Sen. Orrin Hatch, R-Utah, the most senior GOP lawmaker, wants incumbent Luther Strange, beaten by Moore in the primary, to launch a write-in bid.

McConnell wouldn’t commit to Strange. “We’ll see,” he said.

A write-in Republican could end up splitting the vote, affording a victory to Jones and shrinking the GOP’s tiny, 52-seat majority to 51 seats.

That's one reason why expulsion could be a more attractive option for Republicans. Instead of losing the seat to a Democrat, Alabama’s GOP governor would be authorized to handpick a replacement, which would ensure a Republican fills the seat until a new election is ordered.

“If McConnell has the votes, I think he would go through with an expulsion vote,” University of Virginia political science professor Larry Sabato told the Washington Examiner.

“McConnell realizes Moore would be a nightmare for the GOP generally and the Republican Senate caucus in particular,” Sabato said. “McConnell has been handed a powerful weapon to use against Moore, and if he can strike cleanly, my guess is he'll do it.”