Women began entering government in bigger numbers in the 1970s, but any rush has stalled. The number of women in Congress is about 19 percent. Research has shown that women are such a minority in government not because they are less likely to win — they are just as likely, over all — but because they are so much less likely to run in the first place.

Political scientists say this so-called ambition gap is because women are less likely to be encouraged or recruited to run, underestimate their own abilities, assume they need to be more qualified than men and view politics as sexist.

Now, Mrs. Clinton’s loss may lend credence to those doubts.

“Because there was general consensus on both sides of the aisle that she was the most qualified presidential candidate we’ve ever seen, and she lost, it reinforces the notion that maybe it’s not even enough to be twice as good to get half as far,” said Jennifer L. Lawless, a professor of government at American University who studies gender and political ambition.

Caroline Elkins, 47, a professor of history at Harvard, said she was profoundly disappointed and could not separate the outcome from Mrs. Clinton’s gender.

“To think that gender wasn’t a factor would be ludicrous,” she said. “You’d be hard-pressed to find someone more qualified than Hillary Clinton, in my view, and yet she was scrutinized above and beyond any male candidate we’ve ever seen.”

That Mrs. Clinton’s flaws were “thrown into a hyperbolic relief,” she said, suggests that being highly qualified for the job was not enough, that a woman still has to be “twice as good and half as threatening” as a man to succeed.

Ms. Friedman, the retired nurse in Berkeley, who made phone calls on behalf of Mrs. Clinton, was convinced that gender was a factor.

“I underestimated the level of misogyny in the country,” she said. “Which is surprising, because usually I see it where it’s not.” But during her calls, she was sometimes met with crude responses.