Washington, Sep 10 : US Vice President Kamala Harris will on Wednesday (6.30 a.m. IST) face the most significant 90 minutes of her political career when she debates her Republican rival in the 2024 race to White House, former President Donald Trump.

Millions of Americans will tune into the ABC News debate to hear from her and see her as they weigh her sudden elevation to the top of the Democratic ticket around 50 days ago, when President Joe Biden dropped out after a dismal performance in the first presidential debate of the 2024 cycle against the same Republican nominee who will stand at an adjacent podium in a studio debate in Philadelphia.

Harris remains a relatively unknown figure in US politics despite her vice-presidency, which is in its fourth year, and two prior years as a member of the US Senate.

She has a chance to define herself in the debate, or be defined by Trump, who is a veteran of presidential debates, this one being his seventh, including three against Hillary Clinton in 2016, two against Biden in 2020, and one in 2024.

On the other hand, this will be Harris' first presidential debate.

Trump will try to use the debate to end a particularly rough few weeks after Biden's exit on July 21. Harris has wiped out the massive lead Trump had over Biden in polls and has consistently outraised him having galvanised the Democratic party, which had no enthusiasm for Biden, and independent voters yearning for a change from the two old men in the fray until then. Biden is 81 while Trump is 78.

Harris and Trump are tied with the former President holding a slim edge in the most recent poll published on Sunday by The New York Times. But it's Harris who is either in the lead or tied with the former President in seven battleground states.

The June debate between Biden and Harris was watched by 30 million Americans. Even if the same number of people tune into the upcoming debate, both Harris and Trump will have the audience they need to buttress their claims to the country's top political job and portray the other person as not qualified for it.

Harris is known to be a combative debater and had shaken up the Democratic primaries by condemning fellow candidate for the nomination in 2019, Biden, for working with segregationists in the Senate and for opposing aspects of mandatory busing for school desegregation.

And in the vice-presidential debate against Mike Pence, she had scored a viral-video moment telling Pence, 'Mr Vice-President, I am speaking.'

Trump has said Harris was 'vicious' and 'horrible' with Pence and that put down may be playing on his mind.

Trump is also a combative debater and can get rough. His advisers would like to see him focus on the three key issues where Republicans have an advantage -- the economy, immigration, and global chaos.

But they will not hold their breath about when Trump decides to go off the issues and launch personal attacks, which is unlikely to endear him with the independent voters.

Trump is likely to face questions on abortion as he has sought to thread the needle on a sensitive issue.

While his MAGA base is stridently opposed to abortion, independent voters, whose support he will need to win the elections, and some Republicans favour exceptions of varying degrees. He has tried to support exceptions for rape and incest and mother's help, saying he wants the issue to be settled by the states.

Harris has her own set of issues on which she has evolved. Fracking, for instance. She had once supported banning fracking. But she doesn't any more.

The difference between then and now is Pennsylvania, a battleground state crucial to win the White House race. Support for fracking is very high in this state -- it supported 121,000 jobs, and guaranteed billions in royalties for 200,000 landowners whose land was used for extracting natural gas through fracking.

Harris will be watched closely also because she has not made many unscripted public appearances. She has not done a single press conference and sat down for only one media interview in which she shared the limelight, and the responsibility, with her running mate Tim Walz, the Governor of Minnesota.

Trump, on the other hand, has done several press conferences and does an interview almost every day.

/IANS