WEST PALM BEACH, Fla. — Donald Trump heatedly rejected new allegations of sexual assault as “pure fiction” on Thursday, hammering his female accusers as “horrible, horrible liars” as the already nasty 2016 presidential campaign sank further into charges and countercharges of attacks on women.

Campaign foe Hillary Clinton was mostly silent on the issue. But Trump faced a passionate rebuke from first lady Michelle Obama, who warned that his behavior “is not something we can ignore.”

After years of working to end “this kind of violence and abuse and disrespect . . . we’re hearing these exact same things on the campaign trail. We are drowning in it,” Obama declared in battleground New Hampshire, her voice cracking with emotion. “We can’t expose our children to this any longer, not for another minute, let alone for four years.”

With Election Day less than four weeks away, Republican Trump was again forced to defend himself against allegations of sexual misconduct, five days after a video surfaced in which he bragged about kissing and groping women without their permission.

Similar behavior was detailed by women who accused Trump in articles published late Wednesday by The New York Times and the Palm Beach Post. Separately, a People Magazine reporter offered a first-person account accusing Trump of attacking her while she was in Florida to interview him and his pregnant wife.

Ever defiant, the New York billionaire denied the allegations and blamed them on Hillary Clinton’s campaign and the complicit news media as he campaigned in Florida. He promised to sue his media critics and said he was preparing evidence that would discredit his female accusers, whom he called “horrible people. They’re horrible, horrible liars.”

“These vicious claims about me, of inappropriate conduct with women, are totally and absolutely false. And the Clintons know it,” he charged. He offered no evidence discrediting the new reports except to ask why his accusers had waited years and then made their allegations less than a month before the election.

His comments came soon after he called a reporter “a sleazebag” for asking whether Trump had ever touched or groped a woman without her consent.

Trump’s attacks on his accusers’ credibility marked an awkward break from campaign manager, Kellyanne Conway, who earlier in the week highlighted a Clinton tweet that said “every survivor of sexual assault deserves to be heard, believed, and supported.”

Conway hoped to encourage more women to come forward with allegations against Bill Clinton, building on the campaign’s Sunday decision to bring three of the former president’s accusers to the second presidential debate. The Republican nominee is expected to promote the women on stage during upcoming rallies and in television interviews, according to a person briefed on the plan but not authorized to discuss it publicly.

They were not on stage with him on Thursday in West Palm Beach, the first of three public appearances scheduled for the day.

Trump running mate Mike Pence ditched the national reporters who pay to travel with his campaign in Pennsylvania. The Indiana governor’s Twitter account showed him meeting with faith leaders and stopping at a restaurant — after a Pence spokesman said the vice presidential nominee was attending closed-door fundraisers.

Republican leaders across the country said they were deeply troubled by the allegations against Trump, but there was no evidence of new defections. Over the weekend, dozens of Republican senators and Congress members vowed they would not vote for him, with many calling on him to step aside.

Some recanted after an aggressive weekend debate performance. And in what he called an increasingly “muddy” election, Arkansas Gov. Asa Hutchison wondered aloud on Thursday what could change voters’ minds at this point.

Raising complaints Republicans have made against Hillary Clinton, he asked during a news conference:

“Is there a deal-breaker out there? How many emails have to be destroyed? How many investigations have to be concluded with question marks? How many comments have to come out from one campaign in reference to religious institutions that raises concerns?”

More Trump accusers may be coming forward, according to attorney Gloria Allred, who said women have contacted her office in recent days.

“The dam has broken, and more women will be coming forward,” she said.

The stories about Trump and his countercharges against Clinton’s husband have plunged an already rancorous campaign to new lows. They also have distracted attention from the release of thousands of hacked emails from Clinton campaign chairman John Podesta that included some potentially damaging information.

A new batch indicated on Thursday that her 2008 presidential campaign had tried to move the Illinois Democratic primary to a later date, believing it might help her. The emails are being parceled out by WikiLeaks.

The real estate mogul has repeatedly insisted this week that Hillary Clinton needs to be imprisoned. “Honestly, she should be locked up,” he told cheering Florida supporters on Thursday.

For Trump, however, the cumulative effect appears to be a tumble in the battleground states he needs to win in November. What was already a narrow path to the 270 Electoral College votes needed for victory has virtually disappeared unless there’s a significant shake-up before Nov. 8.

He promised Thursday to focus on issues in the final weeks, even as his campaign crafted plans to highlight decades-old accusations against Clinton’s husband.

Trump confidant and informal adviser Roger Stone has long encouraged him to make Bill Clinton’s alleged assaults a centerpiece of the campaign. Steve Bannon, the campaign’s chief executive, until recently ran a conservative website that eagerly promotes conspiracy theories about the Clintons.

Back in New Hampshire, Michelle Obama said, “Enough is enough.”

“In our hearts, we all know if we let Hillary’s opponent win this election, then we are sending a clear message to our kids that everything they are seeing and hearing is perfectly OK,” she said. “We are telling our sons it’s OK to humiliate women. We are telling our daughters this is the way they deserve to be treated. We are telling all of our kids that bigotry and bullying is perfectly acceptable.”

Peoples reported from Washington. AP writer Michael Casey in Manchester, New Hampshire, Brian Slodysko in Allentown, Pennsylvania and Jack Gillum in Washington contributed to this report.