Moore, an outspoken Christian conservative and former state Supreme Court judge, attacked a Washington Post report that he had sexual contact with a 14-year-old girl and pursued three other teenagers decades earlier as "completely false and misleading."
In an interview with conservative radio host Sean Hannity, he did not wholly rule out dating teenage girls when he was in his early 30s.
Asked if that would have been usual for him, Moore said, "Not generally, no." He added: "I don't remember ever dating any girl without the permission of her mother." As for the encounter with 14-year-old Leigh Corfman, as described by Corfman in Thursday's Post article, he said, "It never happened."
The story has produced a wave of concern among anxious GOP officials in Washington but little more than a collective shrug from many Republicans in Alabama, which holds a special election on Dec. 12 to fill the seat previously held by Attorney General Jeff Sessions.
"Humphrey Bogart started dating Lauren Bacall when she was a teenager," said state Auditor Jim Ziegler, referring to the then-19-year-old actress.
"I'll always vote for him," said 28-year-old Erica Richard, of Altoona, Alabama, adding that she wouldn't change her mind even if the allegations of sexual misconduct are proven true. "He's a good man. I love him and his family, and they are all good people."
Paul Reynolds, Alabama's Republican National Committeeman, called it "a firestorm designed to shipwreck a campaign in Alabama. I think it's sinister."
Despite such support, experienced Republican operatives believe the Alabama Senate seat, held by the GOP for the last 20 years, is now at risk.
They fear the controversy could exacerbate the party's broader Trump-era challenge in appealing to college-educated suburban voters - the same group that fueled a big Democratic victory in the Virginia governor's race this week.
Those familiar with recent polling of the Alabama race suggest it was always going to be close despite the state's strong Republican leanings - largely because of Moore's controversial past.
In the immediate aftermath of the Post report Thursday, a wave of national Republican leaders called for Moore to drop out of the race if the allegations are true. They included the White House, the head of the House Freedom Caucus Mark Meadows, Senate Majority Leader Mitch McConnell and Texas Sen. Ted Cruz.
It got worse Friday.
The Senate GOP's campaign arm formally ended its fundraising agreement with Moore.
The GOP's 2012 presidential nominee Mitt Romney condemned his colleagues' caveat - only if the allegations are true.
"Innocent until proven guilty is for criminal convictions, not elections. I believe Leigh Corfman," he said of the Alabama woman who said Moore molested her when she was 14. "Her account is too serious to ignore. Moore is unfit for office and should step aside."
Facing a tough re-election, Rep. Barbara Comstock, R-Va., likened Moore to Hollywood producer Harvey Weinstein, former Rep. Anthony Weiner and former Fox News executive Roger Ailes, all men accused of sexual misconduct.
"The defense from some of his supporters is beyond disgusting," Comstock wrote. "Moore should not serve in the U.S. Senate."
Sens. Mike Lee, R-Utah, and Steve Daines, R-Mont., withdrew their endorsements.
Yet there is no sign Moore is going away quietly. And the Alabama secretary of state's office reported that it's too late to remove his name from the ballot.
The Republican Party's options, including the possibility of a write-in campaign, "are all being researched," said Steven Law, who leads the pro-Republican Senate Leadership Fund.
Those who think Moore should be replaced have little hope of that happening.
"I don't think anyone expects Roy Moore to drop out of this race," Law said. "I think he enjoys being an object of intense controversy. The fact that this has happened may make him even more committed."
Moore was twice removed from his state Supreme Court position, once for disobeying a federal court order to remove a 5,200-pound granite Ten Commandments monument from the lobby of the state judicial building, and later for urging state probate judges to defy the U.S. Supreme Court decision that legalized gay marriage.
He also previously said homosexuality should be illegal, and last week he refused to back off comments that Rep. Keith Ellison, D-Minn., should not be allowed to serve in Congress because he's a Muslim.
Virtually the entire Republican establishment - including President Donald Trump - opposed Moore's primary bid in September.
In Friday's radio interview, Moore cast the Post story as an effort by Democrats - "and maybe even establishment Republicans" - to undermine his campaign. He also mentioned an effort to investigate his accusers.
"We're also doing an investigation and we have some evidence of some collusion here, but we're not ready to put that to the public just yet," he said without elaboration.
The lawyer for Gloria Deason, one of the women cited in the Post story, issued a statement Friday saying Deason has no affiliation with either the Republican or the Democratic party, and has never contacted Moore's election opponent, Democrat Doug Jones.
The lawyer, Paula Cobia, said, "It is reprehensible that so many Alabama Republican officeholders and leaders of their party have rejected wholesale the magnitude of evidence reported in The Post."
Democrats, meanwhile, were quietly stepping up their mobilization efforts in Alabama, though being careful not to publicly ignite partisan backlash by attempting to capitalize on the troubling allegations.
Jones stood to capitalize in places where Moore had shown weakness in past statewide elections. Some Republicans conceded that Moore would likely suffer in the state's reliably, mainstream-Republican suburbs.
In Shelby and Baldwin counties - suburban Birmingham and Mobile - Moore ran more than a dozen percentage points behind Romney in his 2012 bid for the Alabama Supreme Court.
"It's a bad situation," said Henry Barbour, a Republican National Committeeman from neighboring Mississippi. "Do people find it believable? If they do, he will lose."
Peoples reported from New York. Associated Press writers Alan Fram in Washington, Thomas Beaumont in Des Moines, Iowa, and Brynn Anderson in Altoona contributed to this report.
Copyright 2017 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.