Political reporters and pundits think Hillary Clinton won the first Democratic presidential debate. The focus groups called it for Bernie Sanders. But the reason for the split should be discouraging for fans of either candidate.

It wasn't because of Bernie's policy ideas but because of his demeanor: he was "strong," "direct," and "powerful," where Clinton was "too tame," focus group members said. This was true across the board. CNN's panel of undecided voters in Nevada, Fox News's group of Florida Democrats facilitated by pollster Frank Luntz; Fusion's focus group of millennial voters in Miami: All went strongly for Bernie, and style was the number one reason.

This would be a little sad under any circumstances: The debate was widely celebrated for focusing on ideas, but voters were judging based on aesthetics anyway. But it's not just sad — it's painful. Because early on in the debate, Hillary Clinton was strong, direct, and powerful in confronting Bernie Sanders about guns. Sanders responded by scolding her for "shouting." After that, she stopped confronting any of her opponents with force — and ended up getting passed over by voters in favor of someone more forceful.

Whether Clinton deliberately changed her behavior after her early attack on Sanders isn't knowable, and it doesn't matter. The point is that she made a negative impression on people both when she was forceful last night, and when she wasn't. Hillary Clinton has, yet again, been entrapped by a sexist double bind.

Passionate women are used to being told that they're angry

There's a phrase called "tone policing" that's become popular among people who think a lot about social justice. Here's what it means: Often, when a woman or a person of color is making an impassioned argument about an issue that matters deeply to her, the person she's talking to (usually a man or a white person) ignores what she's saying and attacks her for how she's saying it. Women who argue passionately are "emotional" or "shrill"; people of color who argue passionately are "angry" or "irrational."

Clinton is no stranger to this line of attack. She's often portrayed as aggressive and angry; in 2009, political commentator Dana Milbank said that if Obama invited her to a "beer summit" she should drink "Mad Bitch" beer. Just this week, the New York Post claimed she was on the verge of a "serious meltdown." Last month, Donald Trump told an audience that Clinton has "become very shrill."

Early in last night's debate, CNN moderator Anderson Cooper asked Clinton directly if she thought Bernie Sanders had been a champion for gun control. "No," she responded. Then she continued to talk about how urgent she felt gun control was as an issue, and argued, passionately, that Sanders's anti-gun-control votes in Congress violated her progressive principles.

Sanders's response: "All the shouting in the world is not going to do what I hope all of us would want."

Clinton wasn't as aggressive — as passionate — in going after her opponents the rest of the night.

Sanders wasn't trying to discredit Clinton for being a woman. Of course not. He was playing fair. It just happened to fall into a very familiar script.

Ideally, a woman would be able to ignore any criticism of her behavior that wouldn't also be leveled at a man. But the job of an elected politician is to care what people think; when a politician does something that alienates voters, she either changes the behavior or she's out of a job. It's impossible to know whether Clinton was deliberately holding herself back for the rest of the debate after Sanders's "shouting" comment — but she's probably very cognizant of trying not to come off too strong in public. Still, even if she didn't deliberately change her behavior, the fact that her attempt to respond forcefully made an immediate negative impression speaks for itself.

"She's not going to change any minds if she's too tame"

From the beginning of the debate to the end, the "shoutiest" candidate was Bernie Sanders himself. Political pundits saw this as cranky and grandpa-like. But the focus groups were totally won over.

All three focus groups went strongly for Sanders. Unfortunately, CNN didn't give its participants airtime to explain their views (or if it did, there is no record of it available online) — but when the Fox News and Fusion facilitators asked participants to explain why they supported Sanders, here were some of the answers:

"Strong." (Fox)

"All this fire." (Fusion)

"Confident." (Fox)

"Direct." (Fox)

"A fireball through the whole debate." (Fusion)

"Powerful." (Fox)

Sanders didn't just gain points for being assertive. Clinton lost them for not being "fiery" enough. One Fox focus group participant admired Sanders for "protecting (Clinton)" when she was asked about her emails and "being a man about it, a gentleman"; another blamed Clinton for not having stood up for herself. "He was stronger on the issue than she was, which scared me, because I wished she would have said it to protect herself … he had to say it for her."

And one of the young participants in the Fusion focus group put it this way: "Hillary Clinton, while professional and posed, she’s not going to win any moderates in the middle. She’s not going to change any minds if she’s too tame the whole time."

For women, "professional and posed" is the goal. For politicians, it's not enough.

Being "professional and posed" is exactly what women are supposed to be instead of "emotional." It's hard enough for most women to strike the "professional" balance properly — to be neither too aggressive nor too shy. But for politicians, simply being "professional and posed" isn't enough. It suggests that you're less than authentic. Instead, politicians are expected to be passionate and charismatic — to display that they don't just believe what they're saying, but that they care deeply about it.

A tweet from one of the facilitators of CNN's focus group suggested Sanders made up serious ground on Hillary in this regard:

Sanders had large gains – and took votes away from Clinton – on the "cares about you" and "understands you" questions. #DemDebate @CNN — Dr. Rita Kirk (@RealTimePolitic) October 14, 2015

At least one focus group, Fusion's, made an effort to get participants talking about the issues. In response to the young man who accused Clinton of being "too calm," Fusion played the clip of Clinton attacking Sanders on guns, which prompted an issue-focused discussion about gun control. But while the participants had articulate (and deeply felt) opinions, as often as not, that wasn't how they evaluated the candidates.

In the eyes of the focus groups, Bernie Sanders won for doing exactly what he scolded Hillary Clinton for doing the one time she tried it. Sanders and Clinton supporters alike should hope that isn't how most of the Democrats who watched the debate are making their decisions about who won.