Adapted from a story by The Washington Post’s Amber Phillips.

Recent polling suggests Democratic primary voters are skeptical a woman can beat President Trump in 2020.

This evidence that gender bias is influencing how voters perceive women running for president is new. Hillary Clinton said misogyny played a role in her 2016 loss.

It fits neatly into research that demonstrates female politicians are held by voters to a much higher standard than men, forcing women to work harder to prove everything from their policy chops to likability.

"There’s such an entrenched stereotype in voters’ minds of what a successful presidential candidate looks like, and that is often an older, white man,” said Amanda Hunter with the nonpartisan Barbara Lee Family Foundation, which advocates for women in politics.

An April national Quinnipiac University poll of the 2020 Democratic primary gets at this potential gender bias brewing in the 2020 Democratic primary. Sens. Elizabeth Warren (Mass.) and Kamala D. Harris (Calif.) are in the mix for the nomination when you ask voters who they’d vote for if the primary were today.

But the women drop precipitously when asked if voters think they could win against Trump. (Pete Buttigieg, the openly gay mayor of South Bend, Ind., also loses support in this question.)

An April Suffolk University poll of New Hampshire Democrats asked those who said they wouldn’t vote for Warren why. A plurality, 18 percent, said it’s because she can’t beat Trump. (A noticeably high amount, 10 percent said it’s because “she seems angry” — another gender-related hurdle that research shows men don’t have to jump over to win votes.)

On the campaign trail, reporters are hearing over and over again that Democratic primary voters like Warren or Harris but they don’t think either senator can win against Trump. The argument goes something like: I’d vote for a woman for president, but I’m not sure my neighbor would.

"I like her a lot, but I don’t think she could win,” Cindy Vander Linden told the Los Angeles Times in Iowa recently of Harris. She has similar hesitancy about Buttigieg because he’s openly gay and was characterized as “resigned” to backing Joe Biden.

"I don’t think they’re strong enough to carry it for themselves,” Norm Duvé told The Post’s David Weigel in Iowa about women running for president. Though impressed with Warren, “I’d like it if Biden ran with one of the good women,” Duvé said.

The thing is, research shows that women tend to win elections at the same rate as men. Last year, women won seats to Congress in record numbers. (Though that record means they now make up just 24 percent of Congress.) Women tied a record for governorships. (A total of nine!)

But gender bias is entrenched. A recent study from the Georgetown University Center on Education and the Workforce found that 13 percent of Americans still think men are more emotionally suited for politics than women. That’s way less than in decades past, but throw this stat on the pile of evidence that shows when it comes to gaining voters’ trust, women have more to overcome than men. Executive offices — as opposed to more collaborative legislative offices — in particular are difficult for women. That’s one reason the presidency has been, to date, unobtainable for women.

"This is the ultimate executive office, the ultimate decision-maker,” Hunter said. “And voters have to be that much more convinced that a woman is qualified."

The serious female contenders in the 2020 Democratic primary seem to get this. The Barbara Lee Family Foundation research shows female candidates pay a higher price than men if they are seen as learning on the job. It’s likely not a coincidence, then, that Warren and other female candidates for president have detailed policy proposals on everything from student-loan debt forgiveness to affordable housing. Warren is selling campaign T-shirts that say “Warren has a plan for that.” By contrast, Buttigieg and O’Rourke — two men with relatively thin résumés running for president — have been piecing together their platforms as they run.

None of this is to say that a woman can’t or won’t be president in 2020. It’s just that if she does, she will have overcome more voter bias than her male opponents. And 1½ years before the election, we’re seeing this take shape.