Biden-Trump is the rematch many voters don't want. Could the debate change their minds?

When President Joe Biden and former President Donald Trump square off on Thursday, they will especially be looking to appeal to undecided or independent voters – but many who spoke with ABC News are not looking forward to the rematch.

While the CNN debate marks the first real showdown between the two candidates in 2024, they debated before in 2020. Some voters said they would be skipping this faceoff and speculated many others would do the same.

Thalia Flores from Nashua, New Hampshire, said she voted for former U.N. Ambassador Nikki Haley in the GOP primary and is now leaning toward casting her vote for Biden, but said she wishes there would be other candidates on the debate stage.

"We will be paying attention, but most people will be tuned out either for summer vacation or they know who they're voting for and nothing will change their mind," Flores said.

Donald Goetz -- a 70-year-old from Bumpass, Virginia, who called himself a conservative but supports Biden -- said he guesses tuning in to the debate won't be a priority for most voters.

"I think most people don't even watch," Goetz said.

Brendan Fitzsimmons, a physician from Saratoga, Wyoming, has described himself as an outlier in the Republican Party because he said he doesn't plan to vote for Trump. He says he has checked out of the election.

"The only thing that interests me about it is whether one of these two guys will flub up so bad because I think both are cognitively challenged," Fitzsimmons said.

He said he was hoping that independent candidate Robert F. Kennedy Jr. would make the stage -- "At least [then] we'd have a little real discussion."

But with regard to the issues, he added, "I'd like to see what they say about the illegal immigration crisis."

Alex Exefili, a 73-year-old in Fredericksburg, Virginia, told ABC News he is an undecided voter leaning toward Biden. But he said he won't be watching, either.

"You're looking at two candidates that don't appeal to me up to some degree. So, I'll be wasting my time watching. I have other things -- better to do," Exefili said.

Marie Mulroy -- a New Hampshire voter who cast her ballot in the state's GOP primary for Haley -- said she doesn't think the debate will change voter minds.

"For me, I am surprised it is going to happen. Whether it means anything depends on the questions and the moderators," Mulroy said. "I don't think it will change any minds."

Independent voter and retired physicist Patrick O'Rourke of Augusta, Georgia -- just around 150 miles from the debate site -- said that he and his wife do plan on watching the debate. O'Rourke had been undecided, telling ABC News in May that he was leaning toward Biden and had definitely ruled out Trump.

By now, O'Rourke said on Tuesday, he's sure he'll be voting reluctantly for Biden, but he'll still be watching the debate "mostly for the vitality of the two candidates… [to see] their demeanors, can they handle the job."

He's hoping Biden strikes a unifying tone: "Biden in 2020 ran as a unifier but governed as a progressive," O'Rourke said. "I don't know whether he will try that again, but I would like to hear more from him about unifying the country."

Vincent from Flagship, Arizona, identified as an undecided voter, but said he hoped to see Biden excel in the debate.

"I would like to see President Biden be sharp, active and alert, firing back on his game," said Vincent, who asked ABC News not to use his last name.

He continued, "the other candidate I do not like."

Josh Hollister, a 50-year-old Republican from Fredericksburg, Virginia, who plans on voting for Donald Trump, recommended the candidates lay off the "personal jabs."

"It's gonna be interesting … because there's a lot of fireworks and a lot of drama," he said.

ABC News' Sarah Beth Hensley contributed to this report.