Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

WASHINGTON — At least 13 Republicans have called for their party's candidate for Senate in Alabama, Roy Moore, to step aside. Two rescinded their endorsements. The Senate's GOP fundraising arm bailed on him.

But like it or not, the party is probably stuck with him.

Moore, in the wake of the Washington Post report that he forced a woman into a sexual encounter when she was 14 and he was 32, tweeted he would "NEVER GIVE UP." He vowed “to stand up and fight back against the forces of evil waging an all-out war” on his campaign. He called the allegations by the Post “false, false, [and] misleading" in a radio interview with Fox News' Sean Hannity. And at a Veterans Day event Saturday, Moore doubled down on his denial, claiming the Washington Post published the allegations in an attempt to sink his campaign.

That seems to foreclose the possibility of Moore heeding his potential future colleagues' advice, slamming the door on any hope the Senate establishment might have had to get his name removed from the ballot before the December 12 general election — already a long-shot, given state laws.

Now Senate Republicans have to decide how to respond if their current position on the allegations — that Moore should drop out if the allegations are proven true — runs its course.

The National Republican Senatorial Committee typically does not waste money on safe races like Alabama, and has made zero independent expenditures on Moore’s behalf, according to FEC records. The Republican National Committee continues to be a part of the joint fundraising agreement with Moore’s campaign and the Alabama Republican Party.

Still, the news that they were dropping out of the agreement, first reported by The Daily Beast, marks a notable step by GOP establishment to distance itself from the embattled candidate.

Sen. Roy Blunt, R-Mo., a member of the GOP leadership, will not appear at a fundraiser for Moore next Friday in Albertville, Alabama that he had been billed as attending, according to an invitation shared with NBC News.

"He won't be in AL next week," said Blunt spokesperson Katie Boyd.

Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

Asked to clarify if Blunt was canceling on the fundraiser, she repeated, "He won't be in AL."

Sen. Mike Lee, R-Utah, meanwhile, requested his picture be removed from a fundraising email Moore sent to supporters in response to the Washington Post report, a spokesperson confirmed. Later, he pulled his endorsement entirely.

"Having read the detailed description of the incidents, as well as the response from Judge Moore and his campaign, I can no longer endorse his candidacy for the US Senate," Lee tweeted.

Having read the detailed description of the incidents, as well as the response from Judge Moore and his campaign, I can no longer endorse his candidacy for the US Senate. — Mike Lee (@SenMikeLee) November 10, 2017

Montana Sen. Steve Daines also tweeted that he was pulling his endorsement and support for Moore.

Overall, however, Washington Republicans have very little leverage over Moore.

Republicans could get behind a write-in candidate, such as Sen. Luther Strange, R-Ala., who lost the GOP primary to Moore. A handful of senators suggested they would support Strange if he launched a bid, and Strange told the Associated Press he would “do some more research” before ruling it out.

But any write-in campaign would be an uphill battle and end up splitting the GOP vote, making it easier for Democrat Doug Jones to win in an upset.

Alabama's RNC 21-member steering committee could convene a special session and vote to remove Moore as a candidate, but that's even less likely, national committeeman Paul Reynolds told NBC News.

"That committee is not going to vote to remove Roy Moore. The only person to remove Roy Moore is Roy Moore," Reynolds said.

The outside groups that have been spending money to boost Moore, such as the Steve Bannon-aligned Great America PAC, seem to be sticking with Moore so far. And Bannon is still backing him, a source close to the former White House chief strategist told NBC News.

Senate rules empower members to police their own ranks, and Republicans could refuse to seat Moore if elected, or eject him later. But that would mean jeopardizing their already narrow majority.

Only 15 members have ever been expelled from the Senate since 1789, according to the Senate Historian. And the chamber typically only refuses to seat potential members when something about their election or appointment is unclear, rather than over anything about their conduct.

Related: Report: Woman Says Roy Moore Initiated Sexual Activity When She Was 14

Meanwhile, Alabama voters seem to have a high tolerance for politicians trying to stick it out through controversy.

After all, the state lost the head of all three branches of its government to scandal in the past year and half, but never at the hands of voters.

Former House Speaker Mike Hubbard won reelection to his seat months after being indicted on 23 felony corruption charges, and was then re-elected Speaker by 99 out of 105 members.

Former Gov. Robert Bentley was finally forced to resign after trying to tamp down a sex and ethics scandal.

Moore himself was suspended as chief justice of the Alabama Supreme Court in 2016 after refusing to comply with the Supreme Court’s gay marriage ruling. But that didn’t stop Alabama Republicans from making him their Senate nominee a year later.