But that equation is misleading. The better explanation for why Warren attracts disproportionate conservative criticism, and has disproportionately high disapproval ratings, has nothing to do with her progressive economic views or her dalliance with DNA testing. It’s that she’s a woman.

Read: Elizabeth Warren doesn’t want to be Hillary 2.0

As I’ve noted before, women’s ambition provokes a far more negative reaction than men’s. For a 2010 article in the Personality and Social Psychology Bulletin, two Yale professors, Victoria Brescoll and Tyler Okimoto, showed identical fictional biographies of two state senators—one male and one female—to participants in a study. When they added quotations to the biographies that characterized each as “ambitious” and possessing “a strong will to power,” the male state senator grew more popular. But the female state senator not only lost support among both women and men, but also provoked “moral outrage.”

The past decade of American politics has illustrated Brescoll and Okimoto’s findings again and again. During the 2012 campaign, Republicans attacked Nancy Pelosi in television commercials seven times as frequently as they attacked her Democratic Senate counterpart, Harry Reid. In 2016, the disparity was three to one. Pelosi’s detractors sometimes chalk up her unpopularity to her liberalism and her hometown of San Francisco. But Reid’s successor as the Democratic Senate leader, Charles Schumer, a liberal from Brooklyn, is far less unpopular than Pelosi—and far less targeted by the GOP.

Or compare Hillary Clinton with the men who preceded her as Democratic presidential nominees. In a spring 2016 study, fivethirtyeight.com subtracted the percentage of Americans who felt “strongly unfavorable” toward Democratic nominees from the percentage who felt “strongly favorable” at the same time in the presidential cycle. For almost every nominee from 1980 to 2012, the result was roughly zero. In other words, the percentage of Americans who really liked them equaled the percentage of Americans who really disliked them, which makes sense, given the roughly even nature of America’s partisan split. (The one exception was Michael Dukakis, who, as a little-known governor in the spring of 1988, enjoyed a net positive score of more than 10 points.)

Then, in 2016, everything changed. The percentage of Americans who felt “strongly unfavorable” toward Hillary Clinton exceeded the percentage that felt “strongly favorable” by 20 points. Was Clinton uniquely liberal or uniquely dishonest or uniquely inauthentic enough—compared with the seven male Democratic nominees who preceded her—to explain such a large disparity? Probably not. Gender likely played a key role.

Read: Why Trump is the favorite in 2020

Now the same dynamic is playing out with Elizabeth Warren. Pollsters keep recording her unusually high unfavorability ratings. Last September, CNN found that Joe Biden’s net approval rating among Democrats and Democratic-leaning independents was 30 points. Bernie Sanders’s was 18 points. Warren’s was two points. In December, when Quinnipiac University surveyed Democrats, Republicans, and independents, Biden’s net approval rating was 20 points. Sanders’s was two points. Warren’s was negative seven points. Warren’s relatively low numbers appear driven by her unpopularity among men. When the University of Massachusetts asked state residents whom they support in the 2020 Democratic primary, Warren tied with Biden among women. Among men, she trailed him by 16 points.