It has not always been this way. When a victory over Joseph Crowley, the 10-term congressman she challenged in the Democratic primary seemed so improbable, he did not rush to join her on stage and argue about housing policy. The two candidates debated twice; on two other occasions Mr. Crowley said he could not attend because of scheduling conflicts, and on one of those he sent a surrogate, Annabel Palma, a former City Councilwoman, which left the impression that the girls ought to just work things out among themselves.

Feminism’s grand resurgence this past year — striking in the results of the Democratic primary in Minnesota’s Fifth Congressional District on Tuesday in which Ilhan Omar, a young Somali immigrant, won in a six-way race that had three male candidates cumulatively receiving less than 9 percent of the vote — seems to have had little effect on heightening the sensitivities of male politicians to the optics of dismissing their female opponents. When women in politics are not facing the tediousness of having men explain things to them, they are often up against the indignities of their apathy.

Debates in particular have long wielded a special power to trigger male condescension. During the first with a female candidate to be televised nationally — the 1984 vice-presidential debate between George H.W. Bush and Geraldine Ferraro — Americans bore witness to Mr. Bush patronizing a prominent congresswoman, who served as the secretary of the House Democratic Caucus, on the subject of foreign policy. (“Let me help you with the difference, Mrs. Ferraro,” he said, “between Iran and the embassy in Lebanon.”)

Before Donald Trump stalked Hillary Clinton on stage, commandeering the frame in one of the 2016 presidential debates, Barack Obama had derided her as “likable enough,” in a primary debate eight years earlier.

Not showing up at all amounts to another expression of entitlement, and when men are the ones not showing up, the implications easily become gendered. In 2014, Zephyr Teachout, a law professor challenging Andrew M. Cuomo in the Democratic primary for governor in New York, hoped to stand next to him and talk about corruption in Albany, Wall Street influence, money in politics, education funding — but he refused, saying, at one point, that he had participated in many debates over the course of his career and that he found some to be “a disservice to democracy.” Later, in the general election, Mr. Cuomo debated his Republican opponent, Rob Astorino, and two other men running on alternate party lines.