Kamala Harris, US Democratic presidential candidate Joe Biden's pick to be his running mate in November's election, has been a trailblazer all her life.

"My mother used to have a saying," the 55-year-old Harris is fond of recounting. "She would say to me: 'You may be the first to do many things, but make sure you're not the last'."

Harris was the first black attorney general of California, the first woman to hold the post, and the first woman of South Asian heritage to be elected to the US Senate.

She is now seeking to become the first female vice president of the United States.

And, with the 77-year-old Biden expected to serve only a single term if elected, Harris would be favourite to win the Democratic presidential nomination four years from now.

That could give Harris a chance to launch a new era in history as the first female president of the United States.

It is the culmination of a remarkable personal story that began over a century ago in a small village in India. There, her grandfather, PV Gopalan, rose from obscurity to become a distinguished civil servant.

In a socially conservative societyAs strict Hindus, Harris's grandparents' marriage was arranged by their parents. Women were not traditionally expected to study or work so, by studying in the US and marrying for love, Kamala's mother broke many social conventions., Gopalan was open-minded. When his daughter Shyamala applied to study at UC Berkeley, he said, "If you get admission, you go."

In the US, Shyamala met Donald Harris, a Jamaican-born Economics student, and in 1964, Kamala was born. She was one of the first children to be bussedIn order to create more mixed schools, some areas transported students from poor black neighbourhoods to predominantly white schools. In debates last year, Joe Biden and Kamala Harris clashed over Biden's past opposition to bussing. to school - and she grew up in the political heat of the civil rights movement.

She called her grandfather "one of the favourite people in my world". When he wasn't teaching her poker, he was writing her letters. His belief in gradual reform shaped her political convictions. "I'm going to try and go inside the system," she said, "where I don't have to ask permission to change what needs to be changed."

So, how might she end up in the White House? As Biden's vice president, she will automatically take over if he falls ill, dies in office, or is impeachedIn the USA, formally accusing a public official of misconduct whilst in office. Three presidents - Andrew Johnson, Bill Clinton, and Donald Trump - have been impeached by the House of Representatives. In all three cases, the Senate voted not to remove them.. But if he serves a full term and does not stand again in 2024, Harris is now the clear frontrunner to replace him as the Democrat candidate.

This would be an astonishing moment in world history. With very few exceptionsIn 2008, Barack Obama became the first non-white American president. Only two of the United Kingdom's 55 prime ministers have been women (Margaret Thatcher and Theresa May)., power has always been held by white men. In the US, women only gained the vote in 1920 and many African Americans were prevented from voting until 1965. Voting a black woman into the Oval Office would show that the world is finally changing.

However, she must first face the fury of Donald Trump. In his opening salvoThe first in a series of questions or statements used to try and win an argument., he called her "nasty", a "phoney" and a "madwoman". Last night, he accused her of failing to meet the immigration requirements to stand for election. Many political commentators are saying she will need every shred of her political experience for the contest that lies ahead.

Yes, Harris is heading for the top job. Barack Obama's election in 2008 showed that Americans were prepared to vote an African American into the White House. The momentum behind the Black Lives Matter movement has accelerated the desire for change. The tide of history is behind Kamala Harris.

No, Obama faced racist abuse and Hilary Clinton faced intense sexism. Harris will have to contend with both. If Biden wins, she must survive four years of vicious political scrutiny. And if Trump wins this November, her presidential hopes will be over for good.