What does it take to be a woman who could sit in office in the White House?
One hundred years almost to the day since American women were granted the right to vote, that question remains yet unanswered.
But on Wednesday, Kamala Harris, the California senator who has been named as the Democrats' 2020 vice-presidential candidate, will take a step closer to answering it.
Should Democrats win in November, she will be a heartbeat away from the presidency - the nearest any woman has yet come to the office.
As Ms Harris becomes only the fourth woman on a major US presidential campaign ticket, she will be faced with navigating the complexities of race and gender in her historic nomination.
Here is how the three other women who have been on a major party ticket - and one pioneering black female candidate who preceded them - addressed what it meant to aim for the mark.
Shirley Chisholm 1972
"I am not the candidate of black America, although I am black and proud. I am not the candidate of the women's movement of this country, although I am a woman… I am the candidate of the people of America". - announcing her candidacy on the steps of the Brooklyn Concord Baptist Church
The first black woman to run for the Democratic presidential nomination was also the first black woman to serve in US Congress, elected to office in 1968 amid a year of racial tension that gripped the country.
She was the only woman to win that year.
By 1972, when the representative from Brooklyn mounted her unlikely campaign in hopes of becoming the Democratic nominee to take on Richard Nixon, the country was in the midst of a vexed debate over ratifying the Equal Rights Amendment (ERA), aimed at levelling legal rights regardless of sex.
Variously described as "A revolutionary, a matriarch and a pest," Chisholm said that being a woman had been a "bigger drawback" for her than being black.
So it took no small amount of gumption and self-assurance to run for the highest US political office in such a political climate, but Chisholm was known to have had these in spades.
A former aide, Robert Gottlieb, told Smithsonian magazine: "She was unafraid of anybody. Her slogan was 'unbought and unbossed.' She was really unbossed."
When it came to the business of politics, she was more pragmatic. Though she was a fierce promoter of women and black Americans, and focused her primary campaign in states where there was support for women's rights and racial equality, she insisted that her appeal was broader.
Besides supporting the ERA, her platform included getting the US out of South East Asia and increasing minimum wage. "In the end, anti-black, anti-female, and all forms of discrimination are equivalent to the same thing: anti-humanism," she wrote in a memoir. Though always a long-shot bid, she made it all the way to the Democratic nominating convention and got over 150 delegate votes.
Geraldine Ferraro 1984
"By choosing a woman to run for our nation's second highest office, you sent a powerful signal to all Americans. There are no doors we cannot unlock." - DNC nomination speech
The only other female Democrat other than Ms Harris to be chosen as a vice-presidential candidate, Ferraro was also the daughter of immigrants and a former prosecutor.
She acknowledged with unusual candour that her selection as Walter Mondale's running mate was made because she was a woman.
"There's no way any presidential candidate is going to choose a woman as a running mate unless he's 15 points behind in the polls" she admitted to a women's caucus group upon her selection.
Borrowing from John F Kennedy, she declared in her nomination speech that a Mondale-Ferraro administration would pass the Equal Rights Amendment, because "the issue is not what America can do for women, but what women can do for America".
As a campaigner, she was known for her steeliness. When negative reports regarding her family's finances came into light amid the campaign, she put on an expert show in crisis management by holding a marathon press conference to address questions from some 250 reporters present.
The upshot was an apology from George Will, a conservative columnist who had written unfavourably about her. The Washington Post dug up his card, which read: "Has anyone told you you are cute when you're mad?" - to which she reportedly replied "vice-presidents aren't cute".
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Sarah Palin 2008
"I was just your average hockey mom… You know, they say the difference between a hockey mom and a pit bull? Lipstick." - RNC nomination speech
The former governor of Alaska was a surprise pick for John McCain's ticket in 2008, but the Republican senator hoped that her reputation as a fierce and folksy conservative woman would appeal to that swathe of the electorate.
As the first female Republican vice-presidential candidate, Mrs Palin deployed a different kind of feminine political appeal - not so much a beacon of the progress of women in public life, but a totem of the strength of conservative values.
Her opposite in the 2008 election was Joe Biden, but in preparing to face-off in their vice-presidential debate, it was said to be the Democrat who was more conscientious of gender. Contemporary news stories reported that Mr Biden took pains to practice with female stand-ins for Mrs Palin to tackle the challenge of "taking on the Alaska governor without coming across as sexist or a bully".
On the campaign trail, she spoke frequently of being a wife and mother but was less inclined to draw direct attention to her status as a possible future female vice-president, saying only that "to have been chosen brings a great challenge".
However, she congratulated Ms Harris when it was announced that the senator would be on the 2020 Democratic ticket, writing: "Climb upon Geraldine Ferraro's and my shoulders, and from the most amazing view in your life consider lessons we learned".
Her advice included that Ms Harris should "trust no one new" and take care not to be muzzled.
Hillary Clinton 2008, 2016
"Although we weren't able to shatter that highest, hardest glass ceiling this time, thanks to you, it's got about 18 million cracks in it and the light is shining through like never before, filling us all with the hope and the sure knowledge that the path will be a little easier next time" - 2008 primary speech conceding to nominee Barak Obama.
"Tonight, we've reached a milestone in our nation's march toward a more perfect union: the first time that a major party has nominated a woman for President. Standing here as my mother's daughter, and my daughter's mother, I'm so happy this day has come." - 2016 DNC nomination speech
Yards of ink have been spilt to dissect the role that gender played in Mrs Clinton's two campaigns for the White House. In 2008, she lost a hard-fought primary to Barack Obama and in 2016 was defeated by Donald Trump in the general election, despite winning the popular vote.
The question of Mrs Clinton's "likeability", which many critics saw as a coded sexist judgement, was first raised in 2008, with even Mr Obama quipping at one point: "you're likeable enough, Hillary".
But it was in 2016 that sexism aimed at Mrs Clinton was nakedly on display. Sexist slurs appeared as slogans on merchandise sold at Trump rallies.
In the aftermath of the election, political scientists and Mrs Clinton herself agreed that sexism played a part in sinking her candidacy.
She reflected that part of the difficulty was that "there weren't any role models for me to compete twice for the presidency, to be the only woman on the stage... I was making it up as I went. I couldn't go, 'Oh, well, how did so-and-so do it?'"
Yet the divisive reaction to Mrs Clinton's most recent run notwithstanding, her campaign coincided with the notion that so-called "women's issues" are relevant not just to liberal female voters, but the broader electorate.
Agenda items like affordable childcare and parental leave were on the Republican radar, too, and although Mrs Clinton did not win the White House, a ceiling of sorts has arguably been shattered in the manner in which the economic, health and social treatment of women are considered mainstream parts of policymaking.
As for a woman winning a place in the West Wing in 2020, even that may not be at the top of Mrs Clinton's political wishlist. As she told the filmmaker Nanette Burnstein earlier this year, there is a "life-or-death political struggle here" and life this election means "somebody who can beat Trump" in the electoral college. "Everything else is a sideshow."