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.