Washington (CNN) Republicans across Congress unleashed forceful condemnations urging Alabama Senate nominee Roy Moore to abandon his bid. But with no sign that he will heed their calls, GOP leaders and rank-and-file members were less clear Monday night on what should be done next if Moore is elected next month.

Multiple scenarios -- from expulsion to write-in candidacies to holding hearings -- were brought up in the halls of Congress.

And Republicans weren't shy in expressing their frustration.

"There's 50 different scenarios," said Sen. John McCain, who has long opposed Moore. "And I'm not going to discuss those."

Sen. Cory Gardner was quick out the gate to say Moore should be expelled if he ends up in the Senate -- something that requires a two-thirds majority vote and hasn't been done in 155 years. Gardner, head of the Senate Republican campaign committee, released a stunning statement, stating clearly that if Moore "refuses to withdraw and wins, the Senate should vote to expel him."

Not long after, Republican Sen. Lindsey Graham fired off a warning shot, tweeting that if "he continues this will not end well for Mr. Moore." Sen. Todd Young of Indiana put out a statement saying "we need to act to protect the integrity of the Senate" if Moore doesn't step aside.

That was all a step farther than what Senate Majority Leader Mitch McConnell had taken Monday morning when he said he believed the women who said Moore pursued relationships with them when they were teenagers and while he was in his 30s. One woman said she was 14 years old when Moore initiated sexual contact with her. On Monday, a separate Alabama women alleged Moore sexually assaulted her when she was a teenager , and described her experience at a news conference, represented by attorney Gloria Allred.

Moore called the accusation "absolutely false," denying that he knew Nelson and adding that he didn't know where the restaurant that she described was.

Monday night, McConnell wasn't ready to address the issue further.

"I said this morning all I'm going to say today," he told reporters who were asking about expulsion. "Others are speaking for themselves, and you all are reporting it."

Some senators argued it was too early to discuss potential Senate action.

"I think it's premature to talk about expelling someone who hasn't been elected," said Sen. John Cornyn, who rescinded his endorsement of Moore earlier in the day. "So, I'm not going to speculate on that."

"You know, we'll see what happens if he's elected," said Sen. Bob Corker, R-Tennessee.

Sen. Richard Shelby, the senior Republican senator from Alabama, said there should be "due process" before expulsion is raised.

"I think before you reach that, you'd be sitting like a juror and you know you'd want to hear the evidence," he said. "It'd be like voting to convict a president and kicking him out without hearing anything."

Sen. Jeff Flake, an Arizona Republican who is not seeking re-election, expressed serious doubt that expulsion would even be an option, saying he didn't think Moore could win the seat amid the allegations. Republicans will hopefully find a write-in candidate to replace him, he added.

"If we can't, there's no way somebody ought to support this Republican," he said.

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What about Jeff Sessions?

When Moore won the Republican primary runoff in September, he defeated incumbent Sen. Luther Strange, who was appointed earlier this year to fill the seat vacated by now-Attorney General Jeff Sessions.

Strange downplayed the idea that he would start a write-in campaign, telling reporters it was "highly unlikely." Earlier Monday, CNN reported that top Senate Republicans were skeptical that Strange would run because they didn't think he could win, according to two senior GOP sources.

Another name that was being tossed around Monday was Sessions, himself. "Write-ins are hard to come about," Shelby said. "Jeff Sessions would be an ideal write-in candidate."

A source close to Sessions said the attorney general has been telling people in Alabama that he's not interested in returning to his old Senate seat, but a senior GOP source told CNN there's movement behind the scenes to push Sessions to consider the idea.

Republican Sen. Ron Johnson of Wisconsin, when pressed on Moore, said "it'd nice if he'd step aside and we could come up with some system for electing a different Republican."

Senators were also asked Monday about another potential scenario — this one pitched by Allred, who called on the Senate judiciary committee to hold a hearing and subpoena Moore.

Cornyn, the No. 2 Republican in the Senate, appeared to reject the idea.

"We are not a court of law," he said.