MANHEIM, Pennsylvania—Donald Trump had a message for all of the men.

"Right now, you say to your wife: ‘Let’s go to a movie after Trump,’" the Republican presidential nominee said, with a pensive look. He waved his hands in and out as if he were pumping an invisible accordion. "But you won’t do that, because you’ll be so high and so excited that no movie is going to satisfy you. Okay? No movie."

Only a couple of days had passed since Trump had bestirred himself in the wee hours to complain, on Twitter, that the former beauty queen Alicia Machado—"my worst Miss U."—was a "disgusting" person with a "past" that was "terrible," contra the claims of his opponent, Hillary Clinton, who had described Machado as some kind of victim. Decades before, Trump had publicly bemoaned Machado's weight gain, allegedly nicknaming her "Miss Piggy."

Well, it was true, wasn't it? She did gain weight! And all the angry women—who had been banging on about how his interrupting in the debate was sexist, and his insults were sexist, and his or any man's trying to explain anything was sexist—piled all over him again, and the Clinton campaign issued yet another indignant press release about Trump's "painful and degrading discourse and actions."

Trump could not be expected to take that lying down, could he? Not when people didn't know the truth—about Machado and her nasty past ("check out sex tape," only there was, it turned out, not really a sex tape), or, for that matter, about that other terrible woman, the one he was running against. He would tell them, the jostling crowd of thousands that filled the massive room, what kind of woman she was.

"She's a sarcastic woman," he said.

"An incompetent woman," he said.

"Hillary Clinton’s only loyalty is to her financial contributors and to herself. I don’t even think she’s loyal to Bill, if you want to know the truth,” he said.

"She's supposed to fight all these different things, and she can't make it 15 feet to her car!" he said. Trump slumped at his lectern and turned to the side as if he were about to fall over. The crowd erupted in gleeful, incredulous laughter. Is he really doing this? "Folks, we need stamina,” he said. “We need energy."

And so the 2016 campaign, which has already exposed so many of our national rifts—class, race, geography—has settled, in its final weeks, on our deepest and most animal fault line, the one that cleaves the human race in two: men versus women, the old-fashioned battle of the sexes. A few days later, a decade-old recording would surface of Trump talking about groping and seducing married women, in keeping with a long history of what he termed “locker-room banter.”

And isn't it fitting? On the one hand, it might be a rich irony that America's first woman to head a major-party ticket finds herself running against the cartoon of masculinity, the parody of machismo, that is Trump. On the other hand, it might not be a coincidence at all.

The crowd had waited hours for Trump to start, filing through metal detectors as "Season of the Witch" played. There were men in work boots, men in polar fleece, men with mullets, men with hair cropped close to their skulls. There were plenty of women, too, but the vibe was unmistakably masculine, loud and aggressive, always churning and going to get food and jostling for position, more monster-truck rally than Indigo Girls concert.

A popular T-shirt says, "Hillary Sucks But Not Like Monica." On the back, it says, "Trump That Bitch."

Another T-shirt says, "Trump: Finally Someone With Balls."

Another T-shirt shows Clinton falling off the back of a motorcycle Trump is riding, and the back of Trump's shirt says, "If You Can Read This The Bitch Fell Off," and Trump has a sly grin on his face. I asked Joe Martin, a tall, thin 25-year-old who works construction, why he was wearing this shirt, and he shrugged and said, "I thought it was funny."

A few months ago, at a Trump rally in California, I met a man, also in his 20s, who had scribbled in big letters on a piece of posterboard, "ONLY ROSIE O'DONNELL," a reference to Trump's claim that, in his feud with the comedian, he had only been insulting her, not all women. He thought it was the funniest thing Trump had ever said.

So here we are with a few weeks to go until the election that feels like it might end history, somewhere in the fraught, contested area between comedy and offense, and the pundits are saying the women's vote is the key to the whole thing. The gap between men and women voters is shaping up to be the biggest in history; husbands and wives are at odds. It is an election about women, but it is also, inextricably, an election about men—a referendum of sorts on American masculinity, in the explosive, outrageous, grotesque form of Donald J. Trump.

"What kind of man," Clinton asked on Twitter, in response to Trump's anti-Machado tirade, "stays up all night to smear a woman with lies and conspiracy theories?"

What kind of man, indeed.

A few months ago, I spoke to Ivana Trump, Donald Trump's first wife and the mother of his three oldest children. Despite their extremely acrimonious divorce—which began with Ivana confronting her husband's paramour, Marla Maples, on the ski slopes, and ended in a tabloid melee—these days Ivana is on friendly terms with her ex-husband, and supports him politically. "He's going to make a great president," she told me.

From the beginning, women, including Republican women, have responded particularly strongly to Trump’s candidacy. They see something in him that men do not: the abusive boyfriend, the cunning seducer. They look at the men he surrounds himself with: the former Fox News head and alleged serial sexual harasser Roger Ailes, the thrice-married former House Speaker Newt Gingrich (who said, of Machado, “You’re not supposed to gain 60 pounds during the year that you’re Miss Universe”).

“It’s so disheartening,” Amanda Carpenter, a conservative commentator and former aide to Senator Ted Cruz, told me. “Trump is everything Republican women have been trying to fight, saying, ‘Oh, we’re not like that!’ The Ailes-Trump-Gingriches of the world need to die or retire. Go to a nursing home where you can hit on the nurses and leave the rest of us alone.”

But the women close to Trump see him differently.

“He really respects women,” Ivana told me in her Czech-accented purr. He had, she recalled, put her in charge of a large portion of the business during their marriage—she fondly recalled rushing around hotel projects picking out slabs of marble while seven months pregnant, and being put in charge of Trump’s Castle when it opened in Atlantic City. "He told me, 'Ivana, I want you to run it,' and it became the most successful casino in the country," she said.

This is the best defense of Trump. That he is, as his daughter awkwardly put it, "gender neutral," an equal-opportunity exploiter and insulter, a man who holds all people to high standards—perhaps crudely or cruelly—but allows them to rise on their merits.

Today, Ivana says, she and Donald have long since put the divorce battle behind them. “For Donald, the divorce was a business deal, and so he had to win,” she said. “Once the financial situation was straightened out, we were perfectly fine.”

But hadn't it been painful, I asked, to be treated like she was disposable, discarded abruptly after more than a decade of marriage for a younger woman? Ivana harrumphed over the phone. “I am Eastern European woman,” she said. “I am strong.”

These days Ivana spends her winters in Florida, summers in the south of France, and the spring and fall in New York. She is a registered voter in Florida and voted early for Donald in the state's March primary. An immigrant herself, she thought building a wall on the Mexican border was “100 percent right—I have no problem with Mexicans coming to our country, but you have to come legally.” She added, “We need immigrants. Americans don’t want to be gardeners.”

I was trying to figure out what the women around Trump said about him. His mother, born Mary MacLeod in Scotland, was a housewife to whom he has credited his “sense of showmanship”; his older sister, Maryanne Trump Barry, is a tough, no-nonsense, Reagan-appointed federal judge. His eldest daughter Ivanka is famously the brains behind the campaign, introducing him at the Republican convention and starring in a new ad. Trump has hired women to top positions in his company; he surrounds himself with beauty queens, models, and club waitresses that he insists must be pretty and young.

After divorcing Ivana, a model, to marry Maples, a beauty queen, Trump moved on to his third wife, Melania, also a model, who is said to be quiet and traditional. He has said he regrets involving Ivana in his business, saying the entanglement of the personal and professional was too much. Listening to Ivana, it occurred to me that she shared her ex-husband’s personality: She was a schemer, a scrapper, a vulgarian, a person who fought for what she thought she deserved.

Ivana has written several books, including a women’s guide to surviving divorce called The Best Is Yet to Come. She travels the world giving inspirational speeches about women's empowerment, she told me. The title of her signature lecture is “The Woman Who Dares.”

Nobody has a problem with a woman being president, okay? It's just this woman, Hillary Clinton, who is defective in so many obvious ways. That's what the Trump supporters say, and they mean it.

"She's female, but is she a woman?" a Trump supporter in Manheim, JoAnne Balshi, tells me. A 69-year-old retiree with a gold cross around her neck, Balshi has come to the rally with her husband. They are such longtime Trump fans that, long before he entered politics, they once traveled to Trump Tower to celebrate his birthday.

"She doesn't wear a dress ever," Balshi continues. "She'll probably show up in a pantsuit for the inaugural. She's not a typical woman—she's not soft. She's so power-hungry, which is not becoming of a woman."

Her husband, Tom, a dentist wearing a Make America Great Again cap, chimes in. "I know women who are CEOs, women who own companies," he says. "There's no glass ceiling for women anymore. It doesn't exist." Of Alicia Machado, he notes, "It's not like she was Ms. Wholesome."

Most Trump supporters I talk to say they wouldn't say the things Trump says about women, and some would like him to apologize. But his brand of masculinity has a powerful appeal to his male supporters—and also to many women. They firmly agree with Trump that Hillary is “playing the woman's card”—using baseless accusations of sexism to silence her critics, or playing the victim to distract from her own missteps. This is largely the view of Machado, too, in whose career they see a double standard: She was fine with being judged for her looks when it benefited her, then cried foul when the judgment turned negative.

“I think it's wrong the way he talks about women, but there are more important things,” says Ethan Stroh, an 18-year-old student looking forward to casting his first vote for Trump. “Plus it was in her contract to stay looking like that. She's just using his mistakes to punish him.”

This is what women do—they manipulate, they punish—and their influence is turning society soft and weak. "Trump is just an alpha male, a macho guy," says Steve Musselman, a 30-year-old truck driver with a chinstrap beard. "Our problem today is the squashing of the ego. The male ego is what has allowed our species to survive. But today everybody's ultra-sensitive."

Anyway, it's clear Trump doesn't hate women—just look at him. "He obviously loves his wife and children," says Richard Hershey, an 86-year-old retired manufacturing supervisor. Of Machado, he says, "If you listen to what Trump said, he was trying to help her. He wanted to work with her and put her on a diet. So what if he jokingly said 'little piggy' or something? That has nothing to do with anything."

Like Trump always says, it is strength, toughness, stamina that America needs. "I want that in a leader, a man who doesn't take no crap," says "Diamond" Mike Allen, a 55-year-old pro wrestler and stand-up comedian. The screensaver photo on his phone shows a plump, naked, wrinkled woman's body with Hillary Clinton's face, sitting atop a wrecking ball that says "Email." He thinks it is hilarious. "Our great leaders were all tough guys," he says. "They demanded respect, and they got it."

It is tempting to see the maleness Trump represents as a relic of an earlier time. But Trump is not really that, as David Brooks observed a few months ago: "It’s not quite right to say that Trump is a throwback to midcentury sexism," the New York Times columnist wrote. "At least in those days negative behavior toward women and family members was restrained by the chivalry code." Trump represents a more brutal, primal, animal version of the male id, one that mates and slays and subdues unrestrained. One that dominates. One that refuses to be humiliated, that always lashes back against the forces trying to subdue it.

"Obama's policies are so divisive, we can't be humans," says Gerry Sarno, a 65-year-old Democrat and retired mapmaker. Everybody needs to learn to take a joke, he says. "You put yourself on a pedestal, you make yourself a target."

Back onstage, Trump glows in the glare of the lights, complaining about the Clinton campaign's enormous volume of television commercials. "She's spending tens of millions of dollars—it's a disgrace!" he says. "This movement is special," he adds. "The people are special. We are going to make America wealthy again. We are going to make America strong again. We are going to make America powerful again."

And the men and women here, who so crave that power, that strength, burst into cheers and applause.