In a new paper, Mr. Autor and three co-authors found that voting patterns had shifted most in the parts of the country that lost the most jobs as a result of increased trade with China. The study, which focused on congressional elections, found that voters in districts with heavy job losses have tended toward ideological extremes, replacing moderates with more conservative or liberal representatives.

“There is this undercurrent of economically driven dissatisfaction that works to the benefit of candidates who are noncentrist, and particularly right-wing candidates,” Mr. Autor said.

In Wyoming’s coal-rich Powder River Basin, where mines have laid off hundreds of workers in a wave of bankruptcies, workers scoffed at the reports of rising wages and falling unemployment.

Not here, they said.

“We are waiting on the election with high hopes that we do get a Republican in there who does understand about working men and women,” said Mark Perkins, 49, who shut down his electrical storefront in the coal town of Wright earlier this year as he lost once-plentiful jobs servicing mines and large generators.

Mr. Perkins said miners and their families had been streaming away from town as the unemployment rate in surrounding Campbell County soared to 7.5 percent in July, from 3.8 percent a year earlier. Families dropped keys on counters and bolted, Mr. Perkins said, leaving quiet streets and a deep resentment at the economic policies supported by President Obama and Mrs. Clinton.

“I’m just doing small electrical jobs to dog-paddle my way through till Mr. Trump gets elected,” he said. “You’re not going to see very many Hillary — or Killary as we call her here — fans. She was so vocal about putting us out of work and putting us down. We’re the scum of the earth.”

Even in regions that are prospering, many workers have seen little wage growth in recent years. The rise in median income was driven mostly by increased employment rather than wage gains.

Cheri Klug, 56, works as a cashier at a Walmart in southern Minnesota, making almost $12 an hour. Her husband, Dave, 62, draws federal disability benefits.

Mr. Klug said life seemed to get a little harder with every passing year.

“I see everything increasing except my benefits and my wife’s wages,” he said.

Mrs. Clinton has proposed an increase in the minimum wage to $12 an hour, which would modestly increase the couple’s income, but Mr. Klug said he planned to vote for Mr. Trump. He likes the idea of a businessman in the White House, he said.

Moreover, he does not like the idea of a government-imposed pay increase. His wife has spent eight years climbing up to her current pay grade, he said, and it wouldn’t be fair for workers who have just joined Walmart to be lifted to the same level.

David Pilot, 56, works as an analyst for a telecommunications firm in Colorado Springs. He said his pay had increased modestly in recent years, by no more than 2 percent a year. Before the recession, he said, he sometimes got 6 percent raises.

Mr. Pilot works in the service sector, as most Americans now do, but he said he was voting for Mr. Trump because of his promises to return industrial jobs to America.

“I like the fact that he recognizes we are playing on an unlevel field,” Mr. Pilot said. He added that he did not think globalization had done any harm to his own career, but that he knew other people who lost work when companies moved overseas.

Polls also show that Americans remain pessimistic about the nation’s economic prospects. They are worried that the floor is going to fall away from under them, just as it did in 2008.

Last week, 26 percent of people surveyed in Gallup’s poll of Americans’ confidence in the economy rated current economic conditions as excellent or good, while 30 percent labeled them poor. Thirty-seven percent of those surveyed said their economic outlook was “getting better” compared with 57 percent who said it was “getting worse.”

Sheryl Fetzer, 58, who lives in suburban Columbus, Ohio, said she missed the 1990s.

“Everybody was fat in the ’90s,” she said. “Everybody had money. It’s not like that today.”

Not even in her well-groomed suburb? “The grocery stores are full,” she allowed. “The mall is full. People are spending. You can say things look good. But I think we’re about to have a big crash.”

The gloom is deepest, however, in the regions where the recovery has been weakest.

Sara Flynn, 55, says she is lucky to be living in “God’s country,” otherwise known as Hebron, Ky., but she is still trying to regain her footing since her high-end design business collapsed in 2010 at the height of the recession.

She got a job paying $8.25 an hour as a cashier in a big-box store, working her way up to supervisor at nearly double the salary, but she hated it.

“One day I just said ‘I can’t do this anymore,’” said Ms. Flynn, who quit last year. With a degree in architectural design and drafting and contacts in the business, she quickly moved to another job at a kitchen design store, but got laid off after six months when business fell off. Having learned how to type on an electric typewriter in high school, she is now taking a computer course at the Brighton Family Center, a nonprofit in Newport, Ky.

Ms. Flynn has four sons in their 20s. Two graduated from college and two did not.

“The ones with the degrees have really good jobs,” she said. As for two who have high school diplomas, “Well, they’re still living at home.” One is juggling three different restaurant jobs, while the other works at a pizzeria and turned their yard into a makeshift service center where he fixes cars.

Ms. Flynn said her parents were “dyed in the wool” Democrats. Her father worked at G.E. for most of his life, designing airplanes, before retiring with a pension, while her mother raised six children.

But Ms. Flynn said she planned to vote for Mr. Trump. She said she had liked Mr. Trump ever since watching his television show, “The Apprentice,” and she believes him when he says he can “make America great again.”

“That’s a bygone era, that’s when America was great,” Ms. Flynn said of her parent’s generation. “It hasn’t been like that for me.”