Swanee Hunt, former US ambassador to Austria, is founder of the Women and Public Policy Program at the Harvard Kennedy School of Government and founder of Seismic Shift, an initiative dedicated to increasing the number of women in high political office. She is also the author of "Rwandan Women Rising." The views expressed in this commentary are her own. View more opinion on CNN.

(CNN) On Thursday, Massachusetts Sen. Elizabeth Warren announced the end of her presidential campaign after a disheartening performance in the primary elections. Now there is only one woman running for the highest office in the land -- a woman who, by any polling metric, has virtually no chance of winning.

In 2007, when Hillary Rodham Clinton first announced "I'm in, and I'm in to win," she stoked hope in all who dream of political parity -- that a woman could soon be president of the United States. In the immediate aftermath of Clinton's 2016 candidacy, and her loss to a flagrant misogynist, countless women ran for public office.

So, it was promising to see six Democratic women step up to contend for president this time around. Even if two -- author Marianne Williamson and Hawaii Rep. Tulsi Gabbard -- seemed to many like longshots, for a variety of reasons, that left four highly qualified women in the race: Warren, Minnesota Sen. Amy Klobuchar, New York Sen. Kirsten Gillibrand and California Sen. Kamala Harris. Now, the chance that a woman will win the 2020 presidential race has imploded.

What happened?

There's no question that sexism played a role in bringing us to this point. But social influences are wicked problems: they are diseases, hard to diagnose, even harder to cure.

As is often, perhaps always, the case, these female candidates seemed held to a higher standard when it came to being presidential, electable -- and even likeable. In fact, for women, those three characteristics war with one another. A woman who seems nurturing (likable) pays a steep price. Gillibrand, chose to take a soft approach by wearing dresses in contrast to the suits (with pants) that many female candidates wear. Yet beyond optics, she took on issues more overtly women-focused than those of her competitors.

And Harris. Did her strong show of boldness, as when she confronted Vice President Biden on race, make her unlikeable? Why was she, like Gillibrand, unsuccessful in garnering support? Beyond garden-variety campaign problems, what unseen forces stood in the way? Harris wasn't simply a black candidate; our former president blazed that trail. She was a black woman.

As the campaign continued, Warren and Klobuchar established themselves as powerful, and presidential -- far more, surely, than most men in the race. Hence The New York Times endorsement of not one, but both. But by then Warren had fallen in the polls. Some questioned her ability to take on President Donald Trump, fueling doubt about her electability. In Nevada, Warren called attention to the no-win situation she faced as a female politician: "If you complain about it, then you are whining," she said . "And if you don't complain about it, the rest of the women think, 'what planet are you living on?' And so, you get caught in between the two."

Klobuchar had taken the approach of emphasizing that she was running on her merits, not her gender -- though she would nonetheless be proud to be the first female president.

Unabashedly, she called out sexism when she commented during one debate, in reference to former South Bend Mayor Pete Buttigieg, that no female mayor of a small city would be in his position in the race.

Was that whining? Questions like this, even when uttered in a seemingly neutral context, are potentially toxic. Women must work doubly hard to not only be tough, but do it in a way that's visibly appealing.

Likeability may be why Warren, in an Instagram video , pulled a Michelob Ultra out of her fridge as she was casually talking in her kitchen.

The irony is, of course, that the most detestable president in memory resides in a White House defiled by corruption, deception, greed, amorality -- in desperate need of a woman to shovel it all out.

Yes, we're seeing progress below the presidential level. Women make up about a quarter of the voting body of the 116th Congress, a record number (although the women in both chambers are predominantly Democrats).

Given that 100 long years ago American women gained the right to vote, it's hard for many of us to fathom the fact we have yet to take our seat behind the desk in the Oval Office. Perhaps in 2020 we'll see a woman vice president. That would be progress, but not the progress the nation needs for truly representative democracy.

In her book "What Happened," Hillary Clinton recounts an apt story that David Foster Wallace told at a 2005 commencement speech at Kenyon College. Two young fish are swimming along when an older fish coming toward them nods and says, "Mornin', boys. How's the water?" The young fish blithely swim on. Eventually, one looks at the other: "What's water?"

In fact, the most important realities can be the hardest for voters to see and talk about. But see and talk we must. Sexism was a force in this year's Democratic primary.

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A day must come when we can watch election results without saying, "We've got to get it right next time."

For the sake of our future, the stage must be reset as we advance women's political leadership at the highest levels. Ultimately, the democracy we have is the one we've made. To borrow from Shakespeare, if there's fault it's not in our stars, but in ourselves.