Harris and Trump debate in crucial election campaign test

Presidential debates play an important role in American politics, and Tuesday night's debate between Donald Trump and Kamala Harris – their only scheduled meeting so far – is perhaps more important than most.

Joe Biden's poor performance in the first presidential debate at the end of June triggered intense pressure within the Democratic Party, ultimately forcing him to abandon his re-election campaign.

Although Kamala Harris has been vice president for more than three years and has been a presidential candidate for seven weeks, she is still a relatively unknown figure to many Americans. In a recent New York Times poll, 28 percent of likely November voters said they needed to know more about the Californian.

That poll found a statistically neck-and-neck race—a result that the latest polls have also shown both nationally and in key swing states. The 2024 presidential race has been filled with historic turmoil, but the American electorate is still sharply—and narrowly—divided.

This underscores the importance of Tuesday night's debate, where even small changes in voter sentiment could make the difference between victory and defeat for the candidates.

For Harris, the debate in Philadelphia is an opportunity to lay out the details in front of an audience of millions – even if she has to face rhetorical fire from her Republican opponent.

But the opportunity is not without risks, as Ms Harris could define herself – and her positions – in a way that damages her electoral prospects. In the past, she has struggled to answer pointed questions under pressure, and her reluctance to give media interviews in the early weeks of her campaign has denied her the opportunity to hone her speaking skills.

Although she has tried to portray herself as a candidate of change in this election, moderators – and the former president – are likely to push her to defend the Biden administration's record, particularly in areas where polls show Democrats are weak, such as border security and inflation.

She will also have to explain why she has abandoned some of the more liberal policies she advocated during her unsuccessful bid for the 2020 Democratic presidential nomination, including recent backtracking on her positions on a fracking ban, decriminalizing border crossing and nationalizing health insurance.

She explained that these changes were made to reflect the new circumstances, but that some voters might see them as political expediency measures.

For Trump, the debate is an opportunity to reclaim the initiative in this election campaign after a month of Democrats dominating political headlines – with their new nominee and an energetic convention. He has a long history of thriving in the spotlight, setting the terms of the political discussion that keep his opponents off balance and put his issues – particularly immigration and trade, where his positions enjoy broad popular support – at the center of the political discussion.

The former president, however, has his own potential pitfalls on Tuesday. His uneven performance during the debate with Mr Biden in June attracted little attention due to his opponent's sometimes disastrous verbal gaffes. Ms Harris will surely present a more agile opponent, and his answers will have to be sharper.

During an economic forum in New York last week, he was unable to provide a clear explanation for his child care policy. Such verbal ramblings during the debate will provide Democrats with plenty of fodder for their campaign.

Trump must also be careful when arguing with the vice president – who is only the second female presidential candidate and the first woman of color. If he comes across as domineering or condescending, he could further damage his already weak support among female voters.

The two candidates prepared for Tuesday night's event in very different ways. The vice president – and former prosecutor – was in Pittsburgh, a few hours' drive east of Philadelphia, to hold mock debates and discuss her policy proposals. The move also allowed her to campaign and capitalize on local media exposure in the largest and most important swing state, Pennsylvania.

Trump – who has participated in presidential debates in the last three elections – has held more informal meetings to review his positions on key issues, among other things. Last week, he participated in a town hall forum hosted by the conservative cable channel Fox News.

Tuesday is likely to bring a contrast in both styles and political views.

Although Election Day is not until November, early voting is scheduled to begin this month in some key swing states, including the crucial Pennsylvania.

While this debate could help set the political climate for the final two months of the 2024 presidential campaign, it will also be the last chance for the two candidates to reach some voters in states where every vote counts.

North America correspondent Anthony Zurcher analyses the White House election campaign in his weekly newsletter US Election Unspun. Readers in the UK can sign up here. Readers outside the UK can sign up here.