While Trump family values may not be particularly honorable, they are perversely traditional. Melania Trump told the R.N.C. audience that “Donald is intensely loyal to family,” a claim belied by his own marital history — she is wife No. 3, and No. 2 was the woman with whom he cheated on No 1. Mr. Trump has children with three different women; he blames giving his wife too much responsibility in his business for his first divorce, and his wife’s wanting him to spend too much time at home with her and their daughter for his second.

The qualities Mr. Trump seeks in his romantic partners are remarkably retro. Melania Trump is a former model with her own QVC jewelry line and skin care brand who emphasizes that her role as a mother comes before all else; Mr. Trump has spoken disparagingly of working women, does little in the way of child care, and expects women to be more aesthetically appealing than intellectually substantive. “We know our roles,” his wife has said. “I didn’t want him to change the diapers or put Barron to bed.” Mr. Trump agrees: “I won’t do anything” to take care of the children, he told Howard Stern in 2005. “I’ll supply funds and she’ll take care of the kids.” By contrast, Mr. Trump took out a campaign ad featuring Ivanka, and said of her: “I am so proud of Ivanka. She is a terrific person, a devoted mother and an exceptional entrepreneur.”

It can feel unfair to criticize political spouses, who are often dragged into the spotlight only because of whom they married. Mr. Trump, though, is running for office, making his treatment of women — personal and political — as relevant as his treatment of his employees or business partners. The distinctions between the Clinton marriage and the Trumps’ reflect an uncomfortable evolution also happening in homes across the United States. In the past half-century, American women have undergone a transformation in roles, and married couples now look a lot more like the Clintons — or Ivanka Trump and her husband, Jared Kushner — than whatever traditional view of women and home life that Mr. Trump holds: Most women work outside the home full time, and men increasingly marry women who are their educational and professional equals.

But the public remains deeply ambivalent about these shifts. Today, 40 percent of women are their family’s primary breadwinners, and nearly 80 percent of Americans agree that women should not return to traditional roles in society. A third still say it’s best for small children if Mom doesn’t work at all. The Republican Party has particularly struggled to accept this new model, and still pushes back on women’s progress by opposing policies that would help women work and plan their families: things like federally funded child care, paid parental leave and access to birth control. Ivanka Trump’s speech on Thursday was closer to a laundry list of the very policies Democrats have promoted and Republicans have tried to block.