Rudy Giuliani on Sunday defended Donald Trump’s attacks on Bill and Hillary Clinton’s marriage, saying “everybody” has faced charges of infidelity.

“It’s fair game,” the top Trump adviser and former New York mayor said.

On Saturday night, Trump told a rally in Pennsylvania that he doubted the constancy of the Clintons’ marriage, saying: “I don’t even think she’s loyal to Bill, you want to know the truth.”

He then asked the crowd: “And, really, folks, really, why should she be, right?”

The baseless accusation, which Trump raised in the context of Bill Clinton’s admissions of infidelities in the 1990s, was defended by Giuliani.

“That was a sarcastic remark pointing out that Bill Clinton has, you know, quite a past,” Giuliani told CNN. “And Hillary Clinton has done quite a job on attacking the people who were victims of Bill Clinton.”

Clinton stood with her husband in the 1990s through two scandals, during which the president eventually admitted to sexual liaisons with Gennifer Flowers, a former model, and Monica Lewinsky, a White House intern. The then first lady called Lewinsky a “narcissistic loony toon”, according to a friend, Diane Blair, whose diaries were released after her death in 2000. Clinton also refused to excuse the “huge personal lapse” by her husband, Blair wrote.

“It’s fair game,” Giuliani insisted, accusing Clinton of “posing as a feminist”, although he did not dispute that there are no grounds for Trump’s aspersion about the Clinton’s marriage. Trump, he said, had in fact been talking about donations by Middle East regimes to the Clinton family charity.

In his speech on Saturday night, Trump said: “Clinton has collected millions of dollars from the same global corporations shipping your jobs and your dreams to other countries.” He did not, however, mention the Clinton Foundation in context of the Clinton marriage.

Giuliani was also forced to defend one of his own remarks. After the first presidential debate on Monday, after which Trump praised himself for not having broached the topic of the Clintons’ marriage, Giuliani said: “If you didn’t know the moment Monica Lewinsky said Bill Clinton violated her and was telling the truth – then you’re too stupid to be president.”

On Sunday, NBC host Chuck Todd pressed Giuliani, who in 2000 announced he was leaving his second wife for his future third wife in a press conference, without having told his current spouse in advance. Todd said: “You have your own infidelity charge.”

“Well, everybody does,” Giuliani replied. “And I’m a Roman Catholic, and I confess those things to my priest. But I’ve never, ever attacked someone who’s been the victim.”

He added: “I think your bringing up my personal life really is kind of irrelevant to what Hillary Clinton did. She’s running for president; I’m not.”

Giuliani also held that he was “the right person to level this charge, because I’ve never made such a charge, and I’ve prosecuted people who’ve committed rape”.

Trump, whose own history includes three marriages and tabloid sagas of infidelity, has struggled throughout his campaign with references to his long history of crude behavior and objectifying insults directed at women.

In the week after the first presidential debate, he repeatedly insulted a former Miss Universe winner, Alicia Machado, whom he called “Miss Piggy” in the 1990s. On Friday, he urged his supporters to “check out sex tape” of Machado, although no such video exists. Hours later, reporters unearthed an explicit video in which Trump made a cameo.

Poll numbers reflect Trump’s struggle to win female voters. In an NBC poll taken after Monday’s debate, 27% of women surveyed said their opinion of Trump had gotten worse and 30% said their opinions of Clinton had improved. Women were also more likely to say that Clinton had won the debate; majorities of men and women have said Clinton performed well in every major post-debate poll.

A CBS/New York Times poll from mid-September found that 55% of women believe Trump does not respect women, and about 50% think his presidency would be good for women. Fifty-two per cent of female respondents said they would vote for Clinton, and 39% said they would vote for Trump.

White people with college degrees have traditionally voted Republican over the last 60 years, but Trump stands poised to lose them, in particularly white women with degrees.