WASHINGTON — A fifth woman accused Roy Moore, the Republican Senate candidate in Alabama, on Monday of making sexual or romantic advances toward her when she was a teenager, as senior Republicans in Washington called for him to drop out of the race and threatened to expel him from the Senate if he wins.
The new accuser, Beverly Young Nelson, said at a news conference in New York that Moore attacked her when she was 16 and he was a prosecutor in Etowah County, Ala.
Nelson was represented at the news conference by Gloria Allred, a New York lawyer who has championed victims of sexual harassment.
“I tried fighting him off, while yelling at him to stop, but instead of stopping, he began squeezing my neck attempting to force my head onto his crotch,” Nelson said in a statement she issued at the news conference. She said Moore warned her that “no one will believe you” if she told anyone about the encounter in his car.
Hours earlier, Senator Mitch McConnell, the Republican leader, said that Moore “should step aside” and that he believes the women who have accused Moore of sexual misconduct when they were teenagers.
“I believe the women, yes,” McConnell said at a news conference in Louisville, Ky. McConnell also said that encouraging a write-in candidate to run in the Dec. 12 special election is “an option we’re looking at.”
Senator Cory Gardner of Colorado, speaking in his role as chairman of the National Republican Senatorial Committee, said that if Moore wins the special election, he should be expelled from the Senate, “because he does not meet the ethical and moral requirements of the United States Senate.”
In a separate development Monday, a fifth woman stepped forward to accuse former President George H.W. Bush of inappropriately touching her.
Roslyn Corrigan told Time magazine that she was 16 when Bush grabbed her buttocks as she posed for a photo with him in 2003 at a gathering of CIA officers north of Houston. She attended the event with her mother and father, who was an intelligence analyst.
‘‘My initial action was absolute horror. I was really, really confused,’’ she told the magazine. ‘‘The first thing I did was look at my mom and, while he was still standing there, I didn’t say anything. What does a teenager say to the ex-president of the United States?’’
A spokesman for the 41st president, Jim McGrath, said Bush regrets any offensive actions. ‘‘George Bush simply does not have it in his heart to knowingly cause anyone distress, and he again apologizes to anyone he offended during a photo op,’’ he said.
Moore, a judge who was twice removed from the state’s high court, first for refusing to remove the Ten Commandments from the Supreme Court grounds, then for refusing to accept same-sex marriage, responded defiantly. He showed no sign of leaving the race.
In an afternoon statement, Moore’s campaign described Allred as “a sensationalist leading a witch hunt, and she is only around to create a spectacle.” The statement, issued before Allred’s news conference in New York, denied again “any sexual misconduct with anyone” by Moore.
Republicans here and in Alabama have been up in arms over the accusations, published last week in The Washington Post, that Moore pursued sexual or romantic relationships with teenagers when he was in his 30s. The reports have upended a race in a state that has not elected a Democratic senator in 25 years.
In a fund-raising appeal, Moore reached out to his supporters with the subject line: “Mitch McConnell’s plot to destroy me.”
“Apparently Mitch McConnell and the establishment GOP would rather elect a radical pro-abortion Democrat than a conservative Christian,” he wrote.
And Moore’s wife, Kayla Moore, lashed out in a Facebook post Monday, complaining about “a witch hunt” in Alabama and claiming that “we are gathering evidence of money being paid to people who would come forward.”
“Washington establishment and Democrat Party will stop at nothing to stop our campaign,” she wrote. “Prayers appreciated.”
But with McConnell now firmly against his election, Moore and his candidacy promise to deepen the divide between Republican leaders in Congress and the populist wing of the party that is standing by the Alabamian.
Another Republican senator, Susan Collins of Maine, also called for Moore to drop out of the race Monday.
Anxious Republican officials spent much of the weekend trying to determine what, if anything, they could do to halt Moore without simply turning over the seat. If Doug Jones, the Democratic nominee, wins, it would narrow the Republican advantage in the Senate to a single seat.
But if Moore stays in and goes on to win, it could leave Senate Republicans with the question of whether to stop him from being seated or seating him and immediately moving to expel him from the chamber.
One idea now being discussed under this scenario, brought up by two White House officials who spoke on condition of anonymity, would be for Governor Kay Ivey of Alabama to immediately appoint Attorney General Jeff Sessions to what had been his seat when it becomes vacant again.
Sessions remains highly popular among Alabama Republicans, but his relationship with President Trump has waned since he recused himself from the investigation of the role that Russia played in last year’s campaign.