Men have begun asking themselves what they can do to intervene in cases of sexual harassment or denigration – how not to stand by silently. Mothers and fathers have been asking how to raise sons who do not act like this.

The Access Hollywood tape induced a stream of defections from high-level Republicans who had not broken with him over the attack on a war hero’s family, the impugning of a judge of Mexican ancestry, or his threats to ban all Muslims from these shores.

Even if their defense of women was based on outdated Victorian notions of chivalry, there was something about Mr. Trump’s unvarnished male entitlement, that droit du seigneur, that many Republican men could not stomach.

Many Republican women, meanwhile, have deserted Mr. Trump. Suburban women – the vaunted soccer moms who have helped Republicans bridge a longstanding gender gap – seem largely out of his reach. The latest CBS poll of probable voters, conducted a few days after the release of the tape, counted 60 percent of women supporting Mrs. Clinton, compared to 24 percent for Mr. Trump.

This has turned out to be an election in which many of the old dog whistle issues about women – working motherhood, single mothers, a woman’s ability to be commander-in-chief, women’s assertiveness and self-confidence – have not seemed to resonate.

Mrs. Clinton, who shied away in 2008 from the historic nature of her candidacy and was wary of presenting herself as an advocate for women, has changed course this time. She is unabashedly speaking out about her commitment to families and children and her identity as a mother and grandmother. Her full-throated rallying cry for women’s control over their own bodies in the debate Wednesday night was unusually blunt and expansive. She did not shy away from defending late-term abortions – often a political minefield.

It’s an open question whether the election of the first female president would prompt an even more blatant and toxic display of sexism, as the election of the first black president forced American racism even more to the surface. But if Donald Trump’s embrace of sexual swagger and hyper-masculinity alienates enough voters to elect a woman, feminism will be in his debt.