Karen Kraushaar, one of the two women who settled sexual harassment claims against Herman Cain with the National Restaurant Association, spoke publicly for the first time on Tuesday about her allegations against him.

Moments later, a defiant Mr. Cain, who is seeking the Republican presidential nomination, once again declared her allegations to have been found “baseless” and repeated his claim that his only offense against her was to have made a gesture about her height.

Mr. Cain’s denials came in a nationally televised news conference in Scottsdale, Ariz., in which he railed against a “Democratic machine” even as Ms. Kraushaar joined Sharon Bialek, a Chicago woman, in publicly accusing Mr. Cain of inappropriate behavior.

Days after declaring that he was moving on from the brewing controversy, Mr. Cain waded back in with an emphatic plea for decency from his longtime lawyer, followed by a rambling defense of his own personal integrity and a condemnation of the media.

Anticipating calls for him to end his campaign, Mr. Cain declared: “That ain’t gonna happen, because I’m doing this for the American people and for the children and the grandchildren. And I will not be deterred by false, anonymous, incorrect accusations.”

Mr. Cain called the news conference to respond to Ms. Bialek’s allegations, made in a dramatic news conference in New York City on Monday. But it started just minutes after Ms. Kraushaar, one of his original accusers, finally began to speak publicly about her experiences with him.

Ms. Kraushaar, a spokeswoman at the Treasury Department, said in an interview that she was upset that her name had leaked into some press reports. But she said she had decided to speak out now that her identity was publicly known.

“When you are being sexually harassed in the workplace, you are extremely vulnerable,” she said. “You do whatever you can to quickly get yourself into a job someplace safe, and that is what I thought I had achieved when I left.”

Ms. Kraushaar had previously allowed her lawyer to challenge Mr. Cain’s denial that he had done anything wrong while at the helm of the restaurant association in the late 1990s. But after Ms. Bialek went public on Monday and several news organizations published Ms. Kraushaar’s name on Tuesday, she said she had decided to talk publicly — at least in a limited way.

She said she did not know whether or how she might tell more of her story, but had been warming “to the idea of a joint press conference where all of the women would be together with our attorneys and all of this evidence would be considered together.”

She said of Mr. Cain: “These allegations can be considered together as a body of evidence.”

Mr. Cain has denied all allegations of sexual harassment. The restaurant association confirmed that the group came to an agreement with a woman who had made sexual harassment allegations made against Mr. Cain and it was clear it was referring to Ms. Kraushaar.

“I reject all of those charges,” Mr. Cain said Monday afternoon about Ms. Bialek. “How can I defend charges when I don’t remember this person by name?” He added a few minutes later, “I don’t even know who this lady is.”