But there are few signs that Republicans have lost their hold in Altoona. The area is represented by Representative John Joyce, a dermatologist elected for the first time in November with more than 70 percent of the vote. The district is largely Catholic and fervently anti-abortion, helping Mr. Trump.

And there are Trump supporters like Sarah Vogel, who said she wanted to live in her hometown to help its revitalization efforts and opened a coffee shop downtown. “He’s doing what he can to help small businesses and rural areas,” she said. “I don’t know if I can give any specifics.”

But, she said, she is “personally a little bit torn” over Mr. Trump’s hard-line immigration policies. While she voted for him in 2016, she is waiting to see who the Democrats nominate before making up her mind this time. Her strong opposition to abortion will weigh heavily in her decision, she added.

Cultural issues could outweigh economic interests for many voters.

Over lunch with his mother at the Black Dog restaurant near Altoona, Dr. Levi Delozier, a Democrat who returned home to practice medicine, said those issues motivated many voters here in 2016.

“I think cultural beliefs and social mores pervade every decision they make,” Dr. Delozier said. “The haze and the fog and the ether of the campaign made people feel like they were better off. I think the current president is very astute at programming his quote-unquote wins, and he is very good at off-loading losses.”