JANESVILLE, Wis. — James Sands was loading his pickup truck with flooring planks on Monday outside Home Depot in Janesville, across the street from a Holiday Inn where Vice President Mike Pence had paid a campaign visit hours earlier.

This year’s presidential race seems “more like a TV show than real life,” Mr. Sands said, taking a break to reflect on a most unusual election season. “I think people, more and more, are becoming disillusioned about the whole political process,” he added.

Janesville, a city of about 65,000 in southern Wisconsin, epitomizes the change and uncertainty felt in Midwestern industrial cities still struggling to recover from the Great Recession. For almost 90 years, Janesville was home to a massive General Motors assembly plant that employed thousands and enabled local suppliers to employ hundreds more. The plant closed in 2009 at the recession’s height.

Lingering hopes that the factory would be resurrected were dashed when the final smokestack that dominated the 300-acre campus was demolished in 2019.

Several shipping warehouses eventually arrived, including a huge Dollar General distribution center. While some residents welcome the new jobs, others say they’re no substitute for highly paid auto work that once guaranteed pensions and lifelong health insurance.

Mr. Sands works at a Staples warehouse in Beloit. “It’s OK for now,” he said, adding that other opportunities had fallen through.

Some here say much has fallen through. There’s a perception that labor unions failed workers in this largely blue-collar town, and anger against the city for raising municipal fees just as wages were lost. “They did it to make up for what they lost from G.M. — they don’t care,” said Lisa Schmaling, 42, a lifelong Janesville resident and a former canning factory worker.

Some voters feel abandoned by one of Janesville’s most famous residents, former Representative Paul D. Ryan, who rose to House speaker only to announce his retirement in 2018 at 48 and move his family to Washington. Mr. Ryan was a Republican darling in Rock County, which nevertheless has voted for a Democrat in eight consecutive presidential elections since 1988, including in 2012, when Mr. Ryan was Mitt Romney’s running mate.

Sharon Austin, 62, a psychotherapist in Janesville, said Mr. Ryan’s Republican successor, Representative Bryan Steil, was working to gain favor, especially among voters who also support Mr. Trump and Senator Ron Johnson.

Some conservative voters, however, also say they’re disillusioned. 

“I’m conservative, but I don’t like a lot of Republicans,” said Jarrod Morris, 51, of Janesville, who described himself as a Trump supporter. “Few have my ideology. They’re weak and ‘Republican in name only.’”

Chris Hionis, 45, of nearby Evansville, said the Republican Party had become “too elitist.” He now supports Mr. Biden. 

“The rampant murder of people of color doesn’t seem to be getting addressed by conservatives the way I thought they would,” Mr. Hionis said. “I can’t call myself the conservative I used to be.”