Vice President Kamala Harris and former President Donald Trump (Photo: Reuters)

Hosted by ABC News at the National Constitution Center in Philadelphia, the debate could be the only time Trump and Harris go head to head on the debate stage.

Tuesday's 90-minute debate, which will be moderated by ABC anchors David Muir and Linsey Davis, will take place without an audience and will be broadcast live on ABC and other platforms like Disney+ and Hulu.

Last Thursday, Harris and Trump accepted the rules set forth for the debate, which will included muting the microphone of a candidate when it is not their turn to speak.

Last Saturday, Trump delivered a speech at a rally in Wisconsin while Harris took the time to prepare for the debate. According to Professor Aaron Kall of the University of Michigan, the outcome of this first, and possibly only, debate will be crucial.

“There’s no other event in the campaign – speeches, press conferences, the conventions – that will gather anywhere near this number, this audience of tens of millions. And so this one night, this one opportunity for both to reach so many people, you know, a minute from a 90-minute debate could impact thousands – tens of thousands – of votes which could be enough for this very close election expected in November,” said Kall.

A poll from the New York Times and Siena College has Trump at 48 percent to 47 percent for Harris among likely voters.

According to the poll, 28 percent of likely voters say they feel like they need to learn more about Harris, compared to 9 percent who say they need to know more about Trump.