WASHINGTON, United States (AFP) — For years Kamala Harris faced criticism that she was not up to the job of being a heartbeat away from the presidency. Now, she finds herself feted by Democrats as their best hope to stop Donald Trump’s comeback.

Despite blazing a trail as the first woman, Black and South Asian vice president in US history, the 59-year-old Democrat long struggled with approval ratings as bad or worse than President Joe Biden’s.

The last 12 months, however, have revealed a transformed Harris.

And with Biden’s endorsement of Harris after stunning the world by dropping his own re-election bid Sunday, she’s suddenly on the cusp of history.

Harris will hope she has done the hard work to earn her full party’s backing in the midst of the crisis.

As the ageing Biden faded over the last year, his “veep” emerged as a force on the campaign trail, pushing for abortion rights and reaching out to core voters, including suburban women and Black men.

With a fondness for the f-bomb and her family nickname of “Momala” going viral, she has also finally started to cut through the noise to voters who previously barely paid attention.

She has also won plaudits in party circles by staying loyal to the 81-year-old president during the last few weeks, even as political vultures circled over his candidacy.

She now is likely to face Trump — a brutal battle against a candidate who defeated Hillary Clinton in her bid become the first female commander in chief in 2016.

The fact that Harris has blamed much of the criticism of her by Republicans on racism and sexism would likely make a win feel even more vindicating for her.

Trump and other Republicans have notably stepped up their attacks on her as Biden’s position weakened and polls showed Harris would fare better against him than Biden.

A child of immigrant parents — her father was from Jamaica and her mother from India — Harris grew up in Oakland, California, in an activist household that saw her attend her first rallies in a stroller.

Her focus on rights and justice saw her build an impressive CV, becoming California’s first Black attorney general and the first woman of South Asian heritage elected to the US Senate.

Harris then went up against Biden in the 2020 primaries. In one stinging attack, she criticised him for allegedly opposing the bussing of students to segregated schools.

“There was a little girl in California who was part of the second class to integrate her public schools, and she was bussed to school every day. And that little girl was me,” she said in a barbed attack on her future boss.

But as his running mate, she consolidated the coalition that helped defeat the incumbent Trump in 2020.

Her transition to the White House, however, proved difficult.

Critics said she was underwhelming and gaffe-prone in a job that has been known to flummox many officeholders.

Struggling to carve out a role, she was tasked by Biden with getting to the roots of the illegal migration problem, but fumbled and then got defensive in response to a question during a visit to the Mexican border.

Unusually high staff turnover fed rumours of discontent in the vice presidential office.

And Republicans relentlessly targeted her as being unfit to take over should the worst happen to America’s oldest-ever president, often resorting to stereotypes her supporters branded as sexist and racist.

Harris told the Wall Street Journal in February: “I am ready to serve. There’s no question about that.”

Things began to change as the 2024 race got underway.

The Biden campaign repeatedly deployed her to battleground states to hammer home the party’s message on abortion rights, with Harris becoming the first vice president to visit an abortion clinic.

Gradually, she began to draw warm and fired-up crowds.

Some of the outreach was, however, cringe-inducing. Earlier this year, she was mocked after she told chat show host Drew Barrymore her family sometimes called her “Momala,” and Barrymore replied: “We need you to be Momala of the country.”

But voters seemed to be switching on.

A clip of her quoting her mother as often saying “You think you just fell out of a coconut tree?” became a meme, with a rising sense among supporters that now could be her time.

If elected, Harris would break one of the highest glass ceilings left for women in the United States — that of occupying the country’s top office.

Her husband, Douglas Emhoff, would also be breaking new ground, moving from being the current Second Gentleman to the country’s first First Gentleman.