US Election: Donald Trump, Kamala Harris set for high-stakes debate that could redefine 2024 race

Democratic Vice President Kamala Harris and Republican US presidential candidate Donald Trump meet for the first time on Tuesday night in their only scheduled debate, a clash that could prove pivotal in their pitched battle for the White House.

The nationally televised debate beginning at 6 am PST on Wednesday takes place just eight weeks before the November 5 election. The race is a close one that could easily swing in either direction and early voting will start in some states in the coming days.

The encounter is particularly important for Harris, with opinion polls showing that more than a quarter of likely voters feel they do not yet know enough about her, in contrast to the well-known former president.

The debate offers Harris, a former prosecutor, a chance to make her case against Trump, whose felony convictions, outspoken backing for supporters convicted in the January 6, 2021, attack on the U.S. Capitol and frequent falsehoods offer plenty of fertile ground.

It will be the first time the two candidates have met and follows weeks of personal attacks on Harris by Trump and his allies that have included racist and sexist insults.

A similar outburst on stage could turn off undecided voters, according to John Geer, a professor at Vanderbilt University and an expert on presidential politics. Harris is prepared for the possibility.

"Donald Trump has a real problem with the truth," she wrote in an X post Tuesday morning that was echoed in "Crowd Size," a campaign ad featuring former President Barack Obama ridiculing Trump's false claims about crowd sizes at his events.

Harris will discuss the economy and her plans for bringing down food and housing prices, her campaign advisers said.

Trump's advisers and fellow Republicans have urged him to focus on Tuesday on illegal immigration and high prices, issues that play well with voters, and on portraying Harris as too liberal for the country.

Lara Trump, the candidate's daughter-in-law, said Trump had prepared for the debate. "He's ready to talk about why your life was better when he was in office," she said on CNN.

Presidential debates do not necessarily change voters' minds, but they can transform the dynamics of a race. President Joe Biden's performance against Trump in June was so damaging that it eventually led him to abandon his campaign.

TIGHT CONTEST

In a contest that could again come down to tens of thousands of votes in a handful of states, even a small shift in public opinion could alter the outcome. The two candidates are effectively tied in the seven battleground states likely to decide the election, according to polling averages compiled by the New York Times.

"There is more for Kamala Harris to gain and more for her to lose," since she remains less known to many voters, said Mitchell McKinney, a former adviser to the US Commission on Presidential Debates.

Viewers will be looking for where she stands on various issues. But just as important, they will be looking to see how she handles herself against Trump.

Trump, by contrast, is already well defined. "You're either for him or against him" at this point, McKinney said.

The 90-minute debate, hosted by ABC News, will take place at the National Constitution Center in Philadelphia. As agreed by the campaigns, there will be no live audience and microphones will be muted when it is not a candidate's turn to speak.

Harris has been preparing in Pittsburgh since Thursday, holding mock sessions on a stage with lights to recreate the debate environment.

Rather than rehearsing, Trump has relied on informal chats with advisers, campaign appearances and media interviews to get set for Tuesday, with former Democratic congresswoman Tulsi Gabbard - who had a memorably hostile exchange with Harris in a Democratic presidential debate in 2019 - offering advice.

On a call with reporters, Gabbard said Trump would treat Harris just as any other opponent.

"President Trump respects women and doesn't feel the need to be patronizing or to speak to women in any other way than he would speak to a man," she said. "He is speaking to Kamala Harris' record, and comparing and contrasting that with his record of success."

While any personal crossfire will get plenty of attention, the two rivals are also likely to skirmish over several major issues.

A Harris campaign official said the vice president is expected to hammer Trump on abortion and describe him as unfit to lead.

Abortion has been a top issue for Harris and Democrats since 2022, when the US Supreme Court - powered by three Trump appointees - eliminated a nationwide right to the procedure in a broadly unpopular decision.

Harris has also sought to tie Trump to Project 2025, a conservative blueprint from the Heritage Foundation think tank that proposes expanding executive power, eliminating environmental regulations and making it illegal to ship abortion pills across state lines, among other right-wing goals.

Trump has offered shifting rhetoric on abortion while distancing himself from Project 2025, even though many of his former advisers were involved in drafting proposals.

For his part, Trump will tie Harris to the Biden administration's immigration policy, attacking them for record levels of migrant crossings before a recent spate of executive orders drove the numbers down dramatically.

He is expected to highlight Harris' past support - since disavowed - for left-wing stances such as banning fracking, portraying her either as a flip-flopper or an extreme liberal in disguise.