Share your thoughts on our News & Insights section. Complete our survey to help us improve.

Harris and Trump make final preparations ahead of crucial presidential debate in Philadelphia

Looking upwards at a US flag between skyscrapers in New York.jpg

Article originally published by The Guardian. Hargreaves Lansdown is not responsible for its content or accuracy and may not share the author's views. News and research are not personal recommendations to deal. All investments can fall in value so you could get back less than you invest.

The pair face-off in the midst of a race that multiple polls show is neck-and-neck.

It was the debate that was never meant to happen.

Donald Trump will take the stage in Philadelphia on Tuesday night to face, not the familiar foe he expected when he agreed to the encounter in May, but an opponent he has never met and has struggled to define; Kamala Harris, the US vice-president, whose emergence as the Democratic nominee has changed the direction, and very nature, of the presidential election.

The Republican nominee anticipated that he would be keeping a date in the City of Brotherly Love for a second engagement with Joe Biden, the US president with whom he had an acrimonious debating history from the 2020 election.

Related: How will Harris debate Trump? Six key moments offer insight

Instead the unprecedented impact of June’s debate in Atlanta between the pair – in which Biden’s halting and incoherent performance led to him withdrawing his candidacy after mounting pressure from his own Democratic party – has left Trump confronting an opponent against whom he has still to decide a settled line of attack.

Harris, for her part, goes into the event having been prepared by aides who have aped Trump’s often vicious and insulting debating technique – especially towards women – and bolstered by her experience from a previous career as a courtroom prosecutor. She is also buoyed by being up against an adversary who was recently convicted of 34 felony charges.

The pair face-off in the midst of a race that multiple polls show is neck-and-neck – both nationally and in key swing states – none more than in Pennsylvania, the site of Tuesday’s debate, with more electoral votes up for grabs than any other battleground state.

Tuesday’s event, hosted by ABC, will take place under the same rules that governed the Trump-Biden debate, with candidates’ microphones being muted when it is their opponent’s turn to speak. Harris’s campaign argued for mics to be kept live throughout – hoping to goad the former president into the undisciplined and unsavoury interruptions that have marred his previous performances.

While Trump was ready to agree, his entourage – determined to keep him focused and on-message – insisted on keeping the original rules.

But it is Trump’s difficulty in coming to terms with Biden’s departure from the race that could decide the contours of the debate, according to Steven Fein, a specialist in presidential debates and professor of psychology at Williams College in Massachusetts.

“I think, maybe the most interesting and potentially explosive element of it is the fact that he clearly was very upset that Biden dropped out and has been replaced by Harris,” said Fein, who suggested the debate had greater potential for mind games and psychological drama than any he had previously studied.

“It’s going to be a mighty task for him to control his tendencies. Whenever he’s baited … by a woman, he’s usually been very nasty. And a woman of colour is just like the nightmare scenario.

“There’s going to have to be some give and take in a way that there didn’t have to be in the first debate, when he didn’t have to say much but just let Biden flail. So the potential for all kinds of drama is great.”

The former president has been preparing for the debate with, among others, Tulsi Gabbard, a former Democratic member of Congress-turned Trump supporter who ran for the party’s presidential nomination in 2020 and memorably tangled with Harris in a primary debate.

In an eve-of-debate call with journalists on Monday, Jason Miller, a Trump adviser, said that it would be Harris who would have difficulty preparing for Trump.

“The fact that Trump is out there every day doing unscripted questions [means] you can’t prepare for him,” he said, comparing it with training to prepare to fight Muhammed Ali. “You don’t know what his style is going to be. He has an amazing mix of humour and charm, as well as hard hitting facts.”

With Hugo Lowell

This article was written by Robert Tait in Washington from The Guardian and was legally licensed through the DiveMarketplace by Industry Dive. Please direct all licensing questions to legal@industrydive.com.