Donald Trump speaks at a campaign event at Trump Doral golf course in Miami.

Donald Trump speaks at a campaign event at Trump Doral golf course in Miami. Carlo Allegri/Reuters

Businessman Donald Trump officially became the Republican nominee at the party’s convention in Cleveland.

Businessman Donald Trump officially became the Republican nominee at the party’s convention in Cleveland.

Businessman Donald Trump officially became the Republican nominee at the party’s convention in Cleveland.

What Donald Trump is doing on the campaign trail

What Donald Trump is doing on the campaign trail

Donald Trump came under intense scrutiny Friday after he disparaged former Miss Universe Alicia Machado in a series of scathing early morning statements on Twitter, including an accusation that she had appeared in a sex tape.

His rival, Hillary Clinton, swiftly seized upon the attacks to characterize Trump as “unhinged.”

The Republican presidential nominee called Machado “disgusting” and a “con” and raised questions about her past in a series of tweets fired off between 3 a.m. and 5:30 a.m., his most negative comments after days of attacks on her.

The former Miss Universe’s story has dominated media coverage of the election since Clinton brought her up at Monday’s debate, where she criticized Trump for denigrating comments he made in 1996 about Machado’s weight.

The fallout has threatened to undermine weeks of carefully choreographed efforts by Trump’s campaign to repair his image after several missteps this summer, most notably his feud with the family of a Muslim American soldier who died in Iraq.

At the Sept. 26 presidential debate, Hillary Clinton knocked Donald Trump for his treatment of former Miss Universe Alicia Machado. Here's what you need to know about Machado. (Monica Akhtar/The Washington Post)

“For the last month, he’d managed to stay on script and read off the teleprompter. We’d almost forgotten what an erratic, wild and mean man he can be. The Machado thing set him off like a keg of dynamite,” said Republican strategist Ana Navarro, who has been very critical of Trump. “It is a shocking smallness and pettiness on his part. It is the Khans and Judge Curiel all over again. He and his wild pack of surrogates have been viciously attacking this woman for five days now,” she said, referring to the soldier’s family and the judge whose impartiality Trump questioned because of his Hispanic heritage.

“Forget being president. This guy isn’t fit to take care of a puppy,” Navarro added.

Clinton’s campaign responded forcefully, accusing Trump of misogyny and questioning his temperament.

Speaking to a late afternoon rally in Coral Springs, Fla., she mocked Trump’s early morning tweet storm and called it a “meltdown.”

“Who gets up at 3 o’clock in the morning to engage in a Twitter attack against a former Miss Universe?” she asked. “Really, why does he do things like that?”

Clinton said Trump’s behavior was “unhinged, even for him” and was further evidence that he is “temperamentally unfit to be president of the United States.”

“A man who can be provoked by a tweet should not be anywhere near the nuclear codes,” she said.

At a rally in Coral Springs, Fla., Sept. 30, Democratic presidential nominee Hillary Clinton attacked her opponent Donald Trump for tweets he sent out in the early hours of the night before. (The Washington Post)

On Friday afternoon, BuzzFeed News uncovered an explicit Playboy video from 2000 in which Trump made a cameo. The film, titled “Playboy: Video Centerfold,” featured nude women in sexual positions. Trump made a brief appearance in the film, according to BuzzFeed, and did not appear in pornographic scenes.

Clinton’s campaign on Friday evening mocked Trump over his appearance in the film.

“There’s been a lot of talk about sex tapes today, and in a strange turn of events, only one adult film has emerged today, and its star is Donald Trump,” Clinton spokesman Nick Merrill told a group of reporters stationed outside a fundraiser in Miami Beach.

Trump offered no evidence to support his allegation that Machado had a sex tape, a rumor that had widely circulated on the Internet. The GOP nominee appears to have been referring to racy but not explicit footage from a Spanish-language reality television show called “La Granja,” on which she appeared in 2005.

In an attempt to discredit Machado, Trump’s allies have also pointed to news reports of an incident in 1998 in Venezuela, in which Machado was suspected of having driven a getaway car for her then-boyfriend after he shot someone. She allegedly later threatened the judge in the case.

No charges were filed against her, and earlier this week, she called those reports “speculation.”

Trump has also alleged that Clinton helped Machado become a U.S. citizen to attack him. There is no evidence supporting that claim, either.

In a statement in Spanish released on her Instagram account Friday, Machado blasted Trump for attacking her “with the goal of intimidating me” through “slurs and false accusations” that she said were circulated by sensationalist journalists. She accused him of decades of misogyny and vowed to continue supporting Clinton’s candidacy.

“When I was just a young woman, the now-candidate humiliated me, insulted me, publicly disrespected me, as he did often in private in the cruelest way. Just like this happened to me, it’s clear over years that his actions and conduct have been repeated with other women for decades,” she wrote in Spanish.

Pastor Robert Jeffress, a vocal Trump supporter and a Dallas-based evangelical leader, defended Trump and said conservative religious voters are unlikely to mind.

“I do not take literally that he has asked people to sit down and watch a sex tape,” Jeffress said. “I don’t think Donald Trump wants people to watch a sex tape. He’s simply saying people should consider her past when they look at the situation.”

Rep. Steve King (R-Iowa), a conservative leader who has endorsed Trump, suggested that Trump should “let some others bring up the points he made in his tweets. Plenty of high-profile voices could have brought his points out.”

“Maybe he got fed up and said, ‘Let’s blow this issue up and put it behind us.’ I get it,” King said. “And I know he has so many Twitter followers, so he thinks he’s the one to make his view penetrate, to get the truth out there in the media. But he can have others do this kind of thing for him.”

When asked about the timing of Trump’s tweets, King said, “Are you sure he got up from bed? He may have never been to bed. I bet he’s not getting too much sleep these days being in the middle of a campaign.”

But Trump’s critics have blasted the GOP nominee for going after Machado so intently, particularly with just a few weeks before the election.

By repeatedly knocking the former Miss Universe, the GOP candidate has given new life to the feud each day since the debate, which most scientific polls show that voters think he lost.

“He is using his platform to try to demean her and to try to tear her down,” said GOP strategist Tim Miller, a vocal anti-Trump Republican. “And the most concerning part about this to me is somebody who is potentially 40 days away from being elected the president of the United States is kept up at night by how he can win a petty feud against a former beauty queen — who he had called ‘fat’ and ‘Miss Piggy.’ ”

Miller added that Trump’s “emotional” response to “petty slights” should give voters pause.

“He is constitutionally incapable of letting these petty slights go. He’s demonstrated time and time again. This is not a strategic choice. He’s not playing 3-D chess. All he’s doing is responding emotionally because he’s been criticized. It’s a terrible trait,” Miller said.

That has played to the benefit of Clinton, who hopes to raise enough concerns about Trump’s treatment of women to further erode his support among female Republicans, particularly those who are college-educated.

“Oh look, Trump is dominating the news cycle again,” Clinton’s press secretary, Brian Fallon, said on Twitter on Friday morning. “Whatever will we do.”

Clinton called Machado early Friday afternoon as the Democratic nominee was driving from an event in Fort Pierce, Fla., to the airport, according to Merrill. She thanked Machado for her courage during “a war of pretty unpleasant words,” Merrill said.

While taking aim at Trump, Clinton also sought Friday to continue her efforts to give voters a reason to support her and not just be against Trump in a race where both have historically high negatives. Earlier Friday, she delivered a half-hour speech on national service, calling for a new part-time reserve force of 5 million mostly young people who could be tapped on a wide range of city and state projects. In her speech, Clinton said her Methodist faith motivated her and that it would make the encouragement of public service “a vital aspect” of her presidency.

Trump appeared unconcerned Friday afternoon: “For those few people knocking me for tweeting at three o’clock in the morning, at least you know I will be there, awake, to answer the call!” he tweeted.

Robert Costa contributed to this report. Wagner reported from Fort Pierce, Fla.

To watch a video about Machado, go to wapo.st/trumpweight.

Correction: A previous version of this story gave the incorrect location of Capt. Humayun Khan’s death.