Mr. Biden’s campaign suggests that not only can men express love for their family members, admit when they’re wrong and tear up in public — but that it’s also manly to do so.

“There are a lot of Biden tropes that link up with masculinity — protecting, serving, sacrificing, being the rock that the family can depend on,” said Matthew Gutmann, author of “Are Men Animals? How Modern Masculinity Sells Men Short,” and an anthropologist at Brown who has studied masculinity around the world.

As for Mr. Trump, Professor Gutmann said: “I think the misogyny is front and center and absolutely essential to his total persona, his total appeal. And not just to men. A lot of women think that’s the way guys should be. They’re not just begrudgingly voting for Trump, but saying, ‘He’s a real man.’”