With twists and turns in the race to Presidential Elections in US, and Kamala Harris standing for the post of President as Democratic Party's candidate is a gamble in itself.

With Kamala Harris now the candidate, she  has to bet how a Black woman can overcome racism, sexism and her own missteps as a politician to defeat Republican Donald Trump.

In more than two centuries of democracy, American voters have elected only one Black president and never a woman, a record that makes even some Black voters wonder if Harris can crash through the hardest ceiling in US politics.

"Will her race and gender be an issue? Absolutely," said LaTosha Brown, a political strategist and co-founder of the Black Lives Matter Fund.

Harris would face other big challenges: if promoted to the top of the ticket, she would have barely three months to campaign and unite the party and donors behind her.

Yet many Democrats are excited about her chances.

Some three dozen Democratic lawmakers have voiced fears that President Joe Biden, 81, will lose an election that the party has cast as a battle for the future of US democracy because he lacks the mental and physical stamina to win and serve four more years.

Many fear Trump and the Republicans could not only take the White House, but both houses of Congress.

Harris, 59, is two decades younger than Trump and a leader in the party on abortion rights, an issue which resonates with younger voters and Democrats' progressive base. Proponents argue she would energize those voters, consolidate Black support, and bring sharp debating skills to prosecute the political case against the former president.

Her candidacy would offer a contrast with Trump and his vice presidential running mate, Senator J.D. Vance, the two white men on the Republican ticket, Brown said.

Her candidacy would offer a contrast with Trump and his vice presidential running mate, Senator J.D. Vance, the two white men on the Republican ticket, Brown said.

"That to me is reflective of America's past. She is reflective of America's now and future," Brown said.