There isn't a "chorus" behind Donald Trump's debate performance, and that could have reverberations on the GOP's congressional races, experts told CNBC's "Squawk Alley" on Thursday.
Trump was doing "fairly well" in a focus group with undecided voters until a few key moments of the debate, said Chris Kofinis, CEO of Park Street Strategies, a public relations and research firm. He said that Trump's remark that Clinton was a "nasty woman," and his comments about accepting the outcome of the election, represent a "blown opportunity" for the Republican nominee.
"People kind of turned on him," said Kofinis, who previously worked for a Democrat, Sen. Joe Manchin. "It really kind of speaks to the larger problem that Trump has had with his entire campaign. He keeps blaming everyone else for his faults, for the flaws."
When asked if he would commit to accepting the result of the race, regardless of outcome, Trump responded, "I will look at it at the time," reaffirming his previous comments that the election is "rigged."
"What I'm saying is that I will tell you at the time. I'll keep you in suspense," Trump said during the final debate at the University of Nevada, Las Vegas, on Wednesday.
Kofinis said that Trump's leadership may "bleed down" to the congressional election, and that there is "unquestionably" political damage within the Republican party. There is "enormous soul searching" in the party right now, said Sara Fagen, CNBC contributor and former Bush-Cheney campaign strategist.
Forty House seats are open to newcomers this year, and more than half are considered "safe" for the current party.
"I think if we lose the House of Representatives, it's going to be a referendum on the type of campaign Donald Trump ran," Fagen said. "I'm not saying we're going to lose the House — I think there's a decent chance, and a good chance, that Paul Ryan will remain Speaker, albeit by a smaller majority. But if we do lose the House, it won't be because of anything that Paul Ryan did."
— CNBC's Christine Wang and John Schoen contributed to this report.