A growing chorus of Republicans, including President Trump and Senate Majority Leader Mitch McConnell (R-Ky.), have called on Senate candidate Roy Moore to withdraw from a special election in Alabama if allegations prove true that the former judge initiated a sexual encounter with a 14-year-old girl nearly four decades ago.

White House press secretary Sarah Huckabee Sanders, who was accompanying Trump as he traveled from China to Vietnam on Friday, said, “Like most Americans, the president does not believe we can allow a mere allegation, in this case one from many years ago, to destroy a person’s life. However, the president also believes that if these allegations are true, Judge Moore will do the right thing and step aside.”

McConnell, in a formal statement on behalf of all Republican senators, said, “If these allegations are true, he must step aside.”

Other Republican senators weighing in included Jeff Flake of Arizona, David Perdue of Georgia, John Thune of South Dakota, Lisa Murkowski of Alaska, Cory Gardner of Colorado, Richard C. Shelby of Alabama and Patrick J. Toomey of Pennsylvania. Sen. John McCain (R-Ariz.) called on Moore to step aside as well — and without couching his statement with “if true” language.

“The allegations against Roy Moore are deeply disturbing and disqualifying,” McCain said. “He should immediately step aside and allow the people of Alabama to elect a candidate they can be proud of.”

Senate Majority Whip John Cornyn R-Tex.) quickly makes comments to journalists about Senate candidate Roy Moore on Thursday. (Melina Mara/The Washington Post)

Vice President Pence also “found the allegations in the story disturbing and believes, if true, this would disqualify anyone from serving in office,” said spokeswoman Alyssa Farah.

Moore has denied the allegations and given no indication that he will exit the race. "Our children and grandchildren's futures are on the line," he tweeted Thursday. "So rest assured — I will NEVER GIVE UP the fight!" Moore also emailed a fundraising pitch off the revelations. "I believe you and I have a duty to stand up and fight back against the forces of evil waging an all-out war on our conservative values," he wrote.

The state Republican Party has the power to disqualify Moore from the election, according to the Alabama secretary of state. If that happens, McConnell and other Republicans would face the challenge of figuring out which candidate would run in Moore’s place — and how to win an election in which it is too late to replace the former judge’s name on the Dec. 12 ballot.

Under Alabama state law, the ballot cannot be changed within 76 days of an election. However, in the event of either disqualification or withdrawal, votes cast for Moore would not be certified.

In addition, state law allows write-in votes to be cast in general elections, as long as the names are for living people and written in without using a rubber stamp or stick-on label. Despite a state law barring candidates from appearing twice on ballots in the same election cycle, Sen. Luther Strange (R-Ala.), who lost in the primary to Moore, would be an eligible write-in candidate, said John Bennett, an official at the state secretary of state’s office.

Several state Republicans suggested Thursday that the party is unlikely to disqualify Moore.

Samuel H. Givhan, the senior vice chairman of the state party, described The Washington Post story as “allegations from somebody who has been silent for over 40 years” who was speaking out just weeks before an election. When asked about the Senate majority leader’s call for Moore to step aside if the accusations are found to be true, Givhan said, “I’m not sure Sen. McConnell has any say so in this.”

Jonathan P. Gray, a Republican consultant in Alabama who is not working with any of the Senate candidates this year, was more pointed: “I think it was already perfectly well stated that no one in Alabama gives a s--- what Mitch McConnell or John McCain thinks we should do.”

A group close to McConnell that spent millions of dollars to oppose Moore in the primary called on Gov. Kay Ivey (R) and the state party to investigate the allegations. “If there’s even a shred of evidence to these accusations, Gov. Ivey and the Alabama Republican Party need to do everything in their power to remove Judge Moore from the ballot,” said Steven Law, chief executive of the Senate Leadership Fund. “There is no place in our party for sexual predators.”

Strange avoided reporters’ questions in the Capitol on Thursday, but Shelby, his Alabama colleague, said: “Luther Strange is a good senator, he’s a friend, and I support him. I don’t know what he’s going to do, but we’ll see what develops.”

In an extensive report published Thursday, The Post detailed the allegations against Moore by the then-14-year-old and three other girls who were between the ages of 16 and 18 when they said the incidents occurred.

None of the women sought out The Post. While reporting a story in Alabama about supporters of Moore’s Senate campaign, a Post reporter heard that Moore allegedly had sought relationships with teenage girls.

Over the ensuing three weeks, two Post reporters contacted and interviewed the four women. All were initially reluctant to speak publicly but chose to do so after multiple interviews, saying they thought it was important for people to know about their interactions with Moore. The women say they don’t know one another.

The news struck the Capitol with a thunderbolt Thursday afternoon. As senators headed in for an afternoon vote on a Transportation Department nominee, reporters swarmed Republicans in a bid to get their reaction.

McConnell was hounded more than usual as he headed to the Senate Chamber, with reporters shouting questions at a lawmaker they know usually stays mum when asked questions in the hallway.

Once he stepped onto the floor, McConnell quickly voted and conferred with aides. Moments later, Strange came to the floor and headed straight for McConnell. They conferred for several moments before McConnell asked an aide to track down his top spokesman, Don Stewart.

“You can’t make this up,” mouthed one of McConnell’s aides to another colleague.

Stewart came to the floor and told McConnell and Strange that a statement was being sent to reporters. In it, McConnell called on Moore to step down if the allegations are true.

Strange, seemingly unsure of what to do, was instructed to vote and leave the chamber as quickly as possible.

McConnell then conferred with other senators, including Rob Portman (R-Ohio), Thom Tillis (R-N.C.) and Thune. Stewart also assured the senators that a statement was out but then, realizing that reporters were watching from above, instructed McConnell, “Please go.”

He walked toward the back door of the Senate Chamber, paused momentarily and stepped out. Several reporters were waiting for him in the Ohio Clock Corridor.

McConnell’s inner circle spent late Thursday morning discussing the repercussions and how Republicans should move forward — and grousing that if Strange, their preferred candidate in the primary, was still the nominee, they would not be answering questions about Moore’s conduct.

“If it’s true, the Republican Party doesn’t have any place for pedophiles and he should step down immediately,” said Josh Holmes, a McConnell confidant and his former chief of staff. “Steve Bannon is responsible,” he added about the McConnell foil and former White House chief strategist, for enabling candidates such as Moore who are out of the GOP mainstream.

That view was shared by Scott Reed, a political strategist for the U.S. Chamber of Commerce, who opposed Moore’s nomination. “Here we go — another Steve Bannon special,” Reed said.

Ed O’Keefe, Karoun Demirjian, Paul Kane and David Weigel contributed to this report.