The already nasty presidential race got even nastier as Donald Trump's crass comments about forcing himself on women dominated the start of the second presidential debate Sunday night.

The release of the 11-year-old "Access Hollywood" video in which Trump describes himself sexually assaulting women was the first topic addressed as CNN’s Anderson Cooper, one of the moderators, repeatedly pressed him on whether he had indeed kissed and groped women without their consent.

"This is locker room talk," Trump said. "I'm not proud of it. I apologized to my family. I apologized to the American people. Certainly I'm not proud it but this is locker room talk."

He tried to turn the conversation to the beheadings and other barbaric behavior of ISIS and the control of the U.S. borders, but finally said, "No, I have not."

Despite his denials, two women have publicly accused him of touching them — kissing and groping without consent.

His Democratic opponent, Hillary Clinton, took the opportunity to attack Trump's lewd remarks and to argue that he is not fit for the office.

"I think it's clear to anyone who heard it that it represents exactly who he is because we've seen this throughout the campaign," she said. "We have seen him insult women, we've seen him rate women on their appearance, ranking them from one to 10, we've seen him embarrass women on TV and on Twitter."

Trump has not only insulted women, but also African-Americans, Latinos, Muslims, immigrants, Hispanics and others, she said.

Relations between the two candidates are so bitter that they did not shake hands before the town-hall style debate, which also was moderated by ABC News' Martha Raddatz. They did shake hands at the end.

The tape has prompted a growing list of Republican party leaders to withdraw support for their nominee and left Trump defiantly rejecting calls to leave the race.

Trump tried to turn attention to Bill Clinton's infidelities instead, tweeting Sunday about Juanita Broaddrick's accusation that the former president had raped her. The nursing-home operator later signed an affidavit saying there was no assault, then recanted the affidavit. Bill Clinton denied the allegation when she first made it and he was never charged.

And immediately before the debate, Trump appeared on Facebook Live with Broaddrick and two other women who have accused Bill Clinton of sexual misconduct, Paula Jones and Kathleen Willey. The accused rapist of the fourth woman in the group, Kathy Shelton, was represented by Hillary Clinton.

"Mr. Trump may have said some bad words, but Bill Clinton raped me and Hillary Clinton threatened me and I don't think there's any comparison," Broaddrick said.

The women were in the audience with the Trump family during the debate, when Trump again said that Bill Clinton's behavior was worse than his words.

"Bill Clinton was abusive to women," he said. "Hillary Clinton attacked those same women."

Trump was already struggling with women, suburban women in particular, who were appalled by his stream of insults. He called Rosie O’Donnell a "big, fat pig," attacked Miss Universe Alicia Machado, for gaining weight after she won the contest and said of his former Republican primary rival Carly Fiorina: "Look at that face. Would anyone vote for that?”

But for many it was the "Access Hollywood" tape that proved a tipping point. An uproar erupted Friday when The Washington Post and then NBC News published the 2005 recording in which Trump is heard demeaning women.

"I'm automatically attracted to beautiful — I just start kissing them, it's like a magnet. Just kiss. I don't even wait. And when you're a star, they let you do it. You can do anything," he tells Billy Bush, then an Access Hollywood anchor and now on the Today show. "Grab them by the p----. You can do anything."

NBC News obtained the tape from Access Hollywood, which is owned and distributed by NBCUniversal, the parent company of NBC News and MSNBC.

Trump, who was newly married to Melania Trump, is heard talking about pursuing a married woman, saying, "I moved on her actually, she was down in Palm Beach and I failed. I'll admit it. I did try to f--- her, she was married ... and I moved on her very heavily."

Trump responded with a statement in which he apologized if anyone was offended and a video in which he said he was wrong and again apologized. Both times he referred to Bill Clinton's affairs and in the video threatened, "Bill Clinton has actually abused women, and Hillary has bullied, attacked, shamed and intimidated his victims."