In reviewing Kamala D. Harris’s performance in Wednesday night’s vice-presidential debate, two thoughts occurred to President Trump.

“Totally unlikable,” he said during an interview on Fox Business. He also called her “a monster” — twice.

Trump, who has never been big on reading, is probably unaware of the historical roots of his likability and monster critiques.

To historians who study women in politics, it was obvious.

“Likability among male politicians is pretty exclusive,” said Claire Bond Potter, a professor of history at the New School and the author of a book on political engagement. “This is part of a bigger problem that women have — a permanent outsider status in politics. They are always in the process of gaining entry.”

One of the ways to deny women entry is to deny anyone would want to be around them in the first place. The suffragists felt this wrath. So did Hillary Clinton. And now Harris is, too.

“One of the things that a man has to do to become likable is to be perceived as the kind of guy you want to have a beer with,” Potter said, referring to a phrase that was often used to describe Bill Clinton, George W. Bush and John McCain. “You know, it’s very rare that one imagines getting to know a woman over a beer. And you never hear anybody say that he’s the kind of guy you’d like to sit down over a glass of wine with, right?”

Trump and other male politicians know how to tap into that history of misogyny.

“These ideas are woven through society and really always have been,” said Allison K. Lange, a professor of history at Wentworth Institute of Technology and the author of “Picturing Political Power: Images in the Women’s Suffrage Movement.”

In her book, Lange examined how the ideas surrounding “political womanhood” took hold in the earliest days of the country when Martha Washington, the dutiful wife of the nation’s first president, became an icon to opponents of giving women the right to vote. This status was pushed — mostly by men, of course — long after Martha’s death.

In the mid-1850s, Lange notes that a popular book titled “The Republican Court; American Society in the Days of Washington” promoted Martha as “a female ideal.” According to the book’s author, Rufus W. Griswold, women who advocated for women’s rights were “curious monsters,” a phrase that has a familiar ring this week.

President William McKinley delivers his inaugural address March 4, 1897. (J. C. Hemment/Library of Congress)

As for the likability ideal, that dates back, according to Potter, to William McKinley, who campaigned for the presidency from his front porch in Ohio so he could stay close to and take care of his ailing wife, Ida.

“There were lots of stories about this in newspapers that made him an empathetic and likable character,” Potter said.

Once political advertising on TV emerged in the 1950s with the candidacy of Dwight D. Eisenhower, likability became a quality ingrained in the narratives around candidate electability — typically to the detriment of women.

Hillary Clinton, for instance, was seen as competent but not altogether likable during her first run for the presidency in 2008. One of the most memorable moments of the campaign between her and Barack Obama occurred during a debate when the likability question came up.

“My question to you,” the moderator said to Clinton, “is simply this: What can you say to the voters of New Hampshire on this stage tonight, who see your resume and like it, but are hesitating on the likability issue, where they seem to like Barack Obama more?”

“Well, that hurts my feelings,” Clinton replied, jokingly. “But I’ll try to go on.”

The audience laughed and applauded.

“He’s very likable,” Clinton said. “I agree with that. I don’t think I’m that bad.”

Obama then interjected.