If there was a single moment that captured what would carry Mrs Hillary Clinton to the 2016 Democratic nomination, it came not during her sun-splashed campaign kick-off in New York last June, or in any of her speeches celebrating hard-fought primary victories over Senator Bernie Sanders.
No, it was the unscripted instant in which a blase Mrs Clinton coolly brushed from her shoulder a speck of lint, dirt - or perhaps nothing at all - as a Republican-led House panel subjected her to more than eight hours of questioning in October over her handling of the 2012 terrorist attack in Benghazi, Libya.
She may not be the orator President Barack Obama is, or the retail politician her husband was. But Mrs Clinton's steely fortitude in this campaign has plainly inspired older women, black voters and many others who see in her perseverance a kind of mirror to their own struggles.
And Mrs Clinton's very durability - her tenacity, grit and capacity for enduring and overcoming adversity - could be exactly what is required to defeat Mr Donald Trump.
As a politician's wife, first lady, senator and secretary of state - and as a two-time candidate for president - Mrs Clinton, 68, has redefined the role of women in US politics each time she has reinvented herself. She has transfixed the nation again and again, as often in searing episodes of scandal or setback as in triumph.
People are so undecided about how they feel about female leadership, and it's something people really struggle with. The ambiguity about Hillary is outside of her. It comes from people's own perspectives.
SENATOR KIRSTEN GILLIBRAND, on how people's attitude affects perceptions.
"She came on the public stage as someone who was a little different," said Ms Ann Lewis, a longtime adviser. "She attracted fascination, devotion and attacks - and the partisan attacks haven't stopped."
ASKING FOR EVERYTHING
You're required to be touchy-feely and smiley and also required to grow a hide like an elephant. Which is it?
JOURNALIST TINA BROWN, on the many expectations.
"Even as first lady, it was 'Who does she think she is?'" said Ms Melanne Verveer, a close friend of Mrs Clinton's who was her White House chief of staff.
Her confidants say it is only fitting that, having overcome so many obstacles before, including some of her own making, she now faces an opponent so eager to go negative with her - and to refight the bare-knuckled brawls that have defined her career.
In her victory speech last Tuesday night, Mrs Clinton said the biggest influence on her life had been her mother, "and she taught me never to back down from a bully - which turned out to be pretty good advice".
It was with that same grit that Mrs Clinton picked herself up after a bruising defeat by Mr Obama in 2008, when she assured a crowd of tearful female supporters, eight years ago to the day, that they had made 18 million cracks in "the highest, hardest glass ceiling".
For 14 straight years, and 20 in all, Mrs Clinton has been named the woman Americans admire most, according to a yearly Gallup poll. But her campaign, and the controversy over her use of a private e-mail server as secretary of state, have taken a toll: Her favourability and trustworthiness ratings have plummeted. And she is being caricatured, once more, as a calculating and inauthentic career politician: Lady Macbeth, now in her own play.
In the same way, her longevity and fame are not undiluted assets: The baggage she brings as a consummate Democratic insider, pointed up most damagingly in the enormous sums she commanded as a paid speaker to Wall Street banks, has weighed her down in an election cycle in which outsiders have had the wind at their backs.
Her career has not taken a predictable route by any stretch. She came of age in the feminist movement in the 1960s at Wellesley College - where she urged her peers to spurn incremental change and instead work at "making the impossible possible" - then was drawn to the South in furtherance of her husband's ambitions. She was one of her husband's chief campaign strategists and overseer of a failed healthcare effort, while holding her marriage together through his sex scandals and impeachment.
CLINTON AND POWERFUL WOMEN
But if she seemed to embody contradictions, they also reflected a society in which expectations of women, and women's expectations for themselves, were rapidly changing.
And it has always been hard to parse opinions about her and about powerful women in general.
Mr Roy Neel, who managed Mr Al Gore's 1992 presidential campaign, said in an oral history of the Bill Clinton years that women in the South particularly disliked Mrs Clinton, the first working mother to serve as first lady and the first - and, so far, the only - to have an office in the West Wing, because she "appeared to be something of an affront to their sense of who they were".
If age-old antipathies to Mrs Clinton can be chalked up in part to Americans' struggles to adjust to changing gender roles at home, at work and in politics, her history of political combat has also left scar tissue that, in part, defines the candidate she is: wide-eyed about the realities of Washington, but cautious and wary to a fault.
Her prolonged contest with Senator Sanders, whose campaign was not widely expected to survive the first few nominating contests, laid bare the cost of that restraint, both in style and substance.
As voters have gravitated to Mr Trump's unchecked impulsiveness and Mr Sanders' unabashed idealism, Mrs Clinton has displayed little of either. "This is not an incremental, cautious election, and being cautious is not her friend," said Ms Anna Greenberg, a Democratic pollster.
"Both primaries exposed the depth of anger and frustration and disgust," Ms Greenberg added. "She has had to, and will have to, adjust to it."
For 14 months, Mrs Clinton's campaign has been out of step with younger voters and with swathes of an angry electorate that has demanded more than the competence and hard work she has promised.
Her difficulties with those voters could be a warning sign.
While her husband could draw on the crisp centrist philosophy of the "third way" Democrats in 1992, when he devoted his candidacy to the "forgotten middle class", Mrs Clinton has struggled to hit upon as simple and clear a rationale for her campaign. And, though she has issued the most detailed policy proposals and positions of anyone in the race, what she truly believes remains a mystery for many voters.
Mrs Clinton has praised Mr Obama's accomplishments over the past eight years, and won roughly 77 per cent of the vote among blacks through the May 10 contests, according to exit polls. But she has also promised to push harder than Mr Obama in extending citizenship to undocumented immigrants, opposed his signature Trans-Pacific Partnership trade deal and outstripped his plans to defeat the Islamic State in Iraq and Syria by calling for a no-fly zone in Syria.
She has praised her husband's economic record as president and offered to put him in charge of reviving some of the hardest-hit regions. But she has also had to repudiate crucial parts of her husband's legacy.
It has not helped that her campaign has cycled through a half-dozen slogans, from championing "everyday Americans" to "fighting for us", "breaking down barriers," and, most recently, "stronger together" - playing on Mr Trump's more divisive remarks about Mexicans, Muslims and other groups.
As Mr Sanders has demonised Wall Street and Mr Trump has disparaged immigrants, and as they have vowed to reverse economic malaise, Mrs Clinton has run on a flinty practicality. The most telling promise she has made is that she will not overpromise.
"We don't need any more of that," she has told voters.
But what she has lacked in rhetorical brio, she has made up for by listening to people's problems and prescribing solutions. She has shed tears in conversations with a man whose mother had Alzheimer's and a woman who lost a child to a gun accident.
And she has shown a vulnerability she did not reveal in 2008, when she campaigned as a strong would-be commander-in-chief, seeking to neutralise any doubts about whether she was tough enough for the Oval Office.
"I am not a natural politician, in case you haven't noticed, like my husband or President Obama," she said in one of her debates with Mr Sanders, a bracingly honest statement.
To her supporters, there may be a kind of strange logic at work. Mrs Clinton is somehow expected to project the mettle of a commander-in-chief, the charisma of a drinking buddy, the warmth of a favourite aunt, they say.
"You're required to be touchy- feely and smiley and also required to grow a hide like an elephant," said journalist Tina Brown. "Which is it?"
An impossible combination, they complain - and if she managed all that, there would no doubt emerge some other vital quality that she was failing to display, because there is no template yet for a female US president.
"People are so undecided about how they feel about female leadership, and it's something people really struggle with," said Democratic Senator Kirsten Gillibrand from New York. "The ambiguity about Hillary is outside of her. It comes from people's own perspectives."
Attitudes about female leadership eventually may change, of course. And in talking to reporters last Monday, hours before reports that she had clinched the nomination, Mrs Clinton looked past November to a time when female presidential candidates may not require quite so much durability to have a shot at the White House.
"It's predominantly women and girls, but not exclusively - men bring their daughters to meet me and tell me that they are supporting me because of their daughters," she said. "And I do think it will make a very big difference for a father or a mother to be able to look at their daughter just like they can look at their son and say, 'You can be anything you want to be in this country, including President of the United States'."
NEW YORK TIMES