Beverly Young Nelson, who said she voted for President Donald Trump last year, gave her statement alongside lawyer Gloria Allred, as Nelson charged that Moore assaulted her in his car when she was 16, after offering to give her a ride home from a restaurant where she was working at the time.
The involvement of Allred swiftly brought charges from Moore supporters that he was the victim of a smear campaign; Moore's campaign echoed that assessment, saying Allred "is a sensationalist leading a witch hunt."
In a series of fundraising emails and statements from his campaign on Monday, Moore gave no sign that he was going to get out of the race.
But while Moore remained defiant, more and more of his possible future colleagues were weighing in against him.
"Roy Moore should immediately drop out of the race," said Sen. Todd Young (R-IN), who also raised the specter of expelling Moore if he wins the December 12 special election.
"I think we should expel him if he gets here, but I don't think it will come to that," said Sen. Jeff Flake (R-AZ).
"I stand with the Majority Leader on this," said Sen. Orrin Hatch (R-UT). "These are serious and disturbing accusations."
"I did not find his denials to be convincing and believe that he should withdraw from the Senate race in Alabama," said Sen. Susan Collins (R-ME).
"I believe the accusations against Roy Moore are disturbing and, if true, disqualifying," said Sen. John Cornyn (R-TX), the second-ranking Republican in the U.S. Senate, as Cornyn moved to "withdraw my endorsement."
"As it stands, I can’t urge the people of Alabama to support a campaign in the face of these charges, without a serious persuasive demonstration that the charges are not true," said Sen. Ted Cruz (R-TX).
National Democrats were trying to stay out of the firestorm in Alabama.
"It’s an Alabama race," said Senate Democratic Leader Charles Schumer. "They’re running it,” as Schumer gave off the feeling that he wanted no hints that national Democrats were involved in helping Democratic candidate Doug Jones at all.