PHILADELPHIA - For the first time this election, former President Donald Trump and Vice President Kamala Harris will be facing off in a debate on Tuesday night. 

Just six weeks ago, President Joe Biden stepped aside and endorsed Harris for the top of the ticket. Tuesday night she will debate Trump in the only scheduled debate before the November election. 

Dr. Matt Motta, an assistant professor at Boston University, says debates often appeal to the base, and those who aren’t politically active don’t tune in. 

He says this could be the debate where the trend changes. 

“So, I'm expecting this debate to potentially be one of the few debates in modern presidential campaign history that actually does move the polls," Motta said. "And so that's something we're going to watch for very closely in the next couple of weeks."

Motta says Trump is a difficult person to debate. 

He says the key to Harris doing well is to be prepared for his debate style. 

“Vice President Harris is not going to have an easy time injecting workshopped lines into the debate,” said Motta. “The way that she's going to be able to handle the debate and, her, her unique, opponent is to simply practice and see what different directions the conversations go.”

He also points out with the average number of viewers not often coming close to the number of voters, it’s traditional media and social media coverage of debates like this one which could change the course of public opinion.

“That is how most voters, that is how most people are going to encounter information about the debate. What clips get chosen to become the soundbites that make the rounds on social media?” he said. “What talking points? Talking heads on cable news choose to emphasize that is going to be almost as important as what goes on during the debate.”