Republican pollster Frank Luntz predicted former President Trump’s performance in the Tuesday night debate will ultimately cost him the election in November.

In a Wednesday interview on "Piers Morgan Uncensored," Luntz criticized the GOP nominee’s performance and pointed to specific moments in the debate against Vice President Harris that he noted were particularly negative.

“It was a pretty negative performance. Pretty pessimistic, cynical, contemptuous,” Luntz told Morgan in the interview, highlighted by Mediaite, adding, “and I think that this will cost him, yes.”

Luntz hesitated, appearing to choose his words carefully.

“I'm trying to decide if I want to go on record, and the answer is yes," he continued. "I think that — that he loses because of this debate performance."

Trump faced off against Harris for the first time Tuesday night, the first time the two candidates had met in person. During the approximately 90-minute debate, Harris sought to bait Trump on a range of issues, including the size of his rallies and world leaders “laughing” at him. Her strategy seemed to pay off, and the former president frequently responded to her provocations.

Early polls also indicate viewers saw Harris as the debate’s winner.

Luntz said he thought it wasn’t that the Democratic nominee won the debate, but “I think more accurately, is that Donald Trump lost.”

“And this is not the worst debate performance I've seen in my career, but it's very close to it,” he added.

Luntz highlighted moments from the debate when he said Trump should have focused on hitting Harris on inflation and economic issues.

“The conversations about people eating dogs and cats, calling the leader of Hungary one of the greatest world leaders, repeatedly missing the opportunity to focus on inflation and affordability and the complete inability to present his point of view without completely tearing into her, into Joe Biden, into whomever was in his sights,” Luntz said.

The Hill has reached out to the Trump campaign for response.