Ambition is a necessary quality for anyone who wants to be President. But Hillary Clinton’s ambition is often portrayed as a shortcoming. Photograph by Matt Rourke / AP

Hillary Clinton has a bragging problem. It’s not that she brags any more than the average politician, and she certainly does so less than Donald Trump. (Who doesn’t?) But bragging, or if you prefer, self-promotion, is still a trap for women in a way it isn’t quite, or not in the same way, for men. There are a lot of reasons why some Democratic voters can’t warm up to Clinton, and many of those reasons are substantive and gender-neutral: voters on the left of the Party prefer the consistent policy positions of Bernie Sanders, particularly on income inequality, the minimum wage, and campaign finance; they object to the slippery expediency that both Clintons have displayed in their long run on the American political stage. But then there are those many, many other ways that Clinton is somehow not allowed to get it quite right; she’s either too hard or too soft, too much or too little of a feminist. There’s always something wrong, even if the particular something is hard to identify and endlessly open to parsing: her laugh, her voice, her ankles, her hair, her pantsuits, her marriage.

Most of all, perhaps, there is something wrong with her ambition: the way she pushes herself forward, her huffing-and-puffing perseverance. She gets compared to Tracy Flick, the grimly determined high-school politician, played by Reese Witherspoon, in the movie “Election.” Clinton lacks Barack Obama’s chill and Sanders’s gruff indifference to matters of personal grooming and style (he can afford it, as no female candidate could). This sort of animus flared to life again earlier in April, when Sanders’s campaign manager, Jeff Weaver, chided the Clinton camp for criticizing the Sanders’s campaign too aggressively. “Don’t destroy the Democratic Party to satisfy the Secretary’s ambitions to become President of the United States,” Weaver said on CNN.

Ambition is a necessary quality, obviously, for anyone who wants to be President. But, in Hillary Clinton’s case, saying she has ambition is often a kind of accusation. Writing on New York magazine’s Web site, Rebecca Traister laid out the subtext of Weaver’s comment: “Bernie Sanders is a kind man whose relaxed and respectful approach to power has led him to come in second to a woman who works too hard and wants to triumph too much; Hillary’s unembarrassed commitment to winning the race not only makes her unappealing but could be ruinous to the party she’s vying to lead.”

As it happens, there is a fair amount of social-science research suggesting that women who would be leaders in their organizations are often punished for displaying the very qualities they need to advance. In a 2010 review of that literature in the Psychology of Women Quarterly, for example, Corinne A. Moss-Racusin and Laurie A. Rudman cite a study that found “male managers were more inclined to work with ‘nice’ women who accepted their initial compensation offers, compared with women who attempted to negotiate for more money. By contrast, negotiating for a higher salary had no effect on managers’ willingness to work with male candidates.”

Analyzing the research, Moss-Racusin and Rudman conclude that, “professional women face a Catch-22: They must overcome negative stereotypes about women by “acting like men,” yet when they do so they risk being penalized for violating gender prescriptions. In fact, self-promoting women are seen as more dominant and arrogant than self-promoting men, whose behavior is consistent with stereotypic expectations.” That double standard, they write, “is a critical barrier to women’s equitable treatment because self-promotion is necessary for career advancement, yet only women risk penalties for it.”

Clinton, as she heads toward another round of primaries next Tuesday—in Pennsylvania, Maryland, Connecticut, Rhode Island, and Delaware—faces a version of this Catch-22, and it’s particularly pointed because, more than anything else, what she has to offer as a candidate is her considerable experience. Sometimes, when she invokes her résumé, she stumbles badly, as in a debate in November, in Des Moines, when Sanders challenged her on her ties to Wall Street, and she invoked 9/11: “We were attacked in downtown Manhattan, where Wall Street is. I did spend a whole lot of time and effort helping them rebuild.” But she ought to be able to boast, for instance, that, as both a former First Lady and a former Secretary of State, and as someone who travelled exceedingly widely in both roles, she has unprecedented foreign-policy expertise. And she shouldn’t be paying a sexist penalty for it.