Democrats See a Blueprint in Fetterman’s Victory in Pennsylvania

“Should you compare Oz to Trump in 2020, or to some version of Romney?” Mr. Casey said.

Rob Gleason, a former chairman of the state Republican Party who lives in central Pennsylvania, rejected the idea that Democrats, thanks to Mr. Fetterman, had made lasting inroads with white working-class voters. Dr. Oz, Mr. Gleason said, lost mostly because Mr. Fetterman succeeded in painting him as a rich out-of-stater with multiple houses — a class-war campaign.

“I’m still mystified how he could do so well because he didn’t release any of his medical records, he didn’t do good in the debate, he embraced Biden,” Mr. Gleason said of Mr. Fetterman, who is continuing to recover from a severe stroke in May. “He’s an odd-looking guy, in shorts and a hoodie. I thought this was going to be easy.

“The class struggle and fact Oz wasn’t from Pennsylvania,” Mr. Gleason continued, “that was the death knell.”

It was rare to find Trump voters in Armstrong County who had crossed party lines to vote for Mr. Fetterman. One of them, Michael Yeomans, 66, a retired heavy equipment operator who supported Mr. Trump in 2016, said he never considered voting for Dr. Oz “based on the things I have seen Dr. Oz do before he was interested in running, like on TV.’’

“I think in the older days,” he added, “they’d call it a snake-oil salesman.”

Emmy McQuaid, a retired teacher who identified herself as a political independent, had a more sympathetic view of Dr. Oz, though she voted for Mr. Fetterman. “I think he’s a good man,” she said. “I’m not sure how his health is going to hold up, but I think his intentions might be good. I think Dr. Oz’s would have too, but I’d like to see John have a go.”

An alternative explanation for why Mr. Fetterman did so much better than Mr. Biden in red counties, besides winning some former Trump supporters, is that a different spectrum of voters turned out in 2022 than during the presidential race two years ago.

Mr. Fetterman, who campaigned aggressively for more than a year in the rural counties before his stroke under the banner “every county, every vote,” may have inspired inconsistent voters who still leaned Democratic to turn out for him.