Donald Trump campaigns in Sterling Heights, Mich., on Nov. 6. (Jabin Botsford/The Washington Post)

Donald Trump won the presidency by turning the Rust Belt red.

On Tuesday night, he swept Pennsylvania, Ohio, Michigan and Wisconsin — states that voted twice for Barack Obama and that rank near the top in manufacturing jobs. Although his promise to restore the glory days of building cars and pouring steel sometimes made him sound like a guy who learned about past-their-prime factory towns by watching “Roger & Me” and listening to “Born in the U.S.A.,” he tapped into a still-strong nostalgia for a time when a young man could go straight from high school to an industrial job that paid enough to support a family.

When Trump Force One flew into Flint, Mich., in August 2015 for the Genesee County Republican Party’s Lincoln Day Dinner, the man who’s now president-elect told an anecdote about seeing “boatloads” of Japanese cars in the Port of Los Angeles, then promised to stop Ford from investing $2.5 billion in Mexican engine plants. He knew his audience.

“Mexico is killing us on trade,” Trump said to cheers from 3,000 listeners, the biggest Lincoln Day crowd in the county’s history. “Mexico is the new China … They’re taking our factories, and they’re rebuilding these massive plants in Mexico.”

“My brothers went to GM out of high school,” said Genesee County Republican Party chairman Michael Moon, who invited Trump to Michigan. “By 1980, that was over. We’ve lost a ton of manufacturing jobs out of this state. They went to Mexico. We’re gonna get killed by these countries. Getting involved in the global economy, you’ve got to have some kind of national pride. We’ll take care of our own country, then if there’s something left for you, we’ll take care of you.”

Clinton, on the other hand, seemed to take the Upper Midwest for granted, never campaigning in Wisconsin and finally making a panicky visit to Detroit on the Friday before the election. In the 1980s, Michigan was the forging ground of the Reagan Democrats: hawkish, socially conservative, suburban, blue-collar workers who ignored the United Auto Workers’ entreaties to vote for Jimmy Carter and Walter Mondale. (Their heartland, Macomb County, just north of Detroit, voted for Obama in 2012 but gave Trump 54 percent of its vote on Tuesday.)

If there’s such a thing as a Trump Democrat, he’s exemplified by Bill Peek, a UAW member who worked 41 years for General Motors at the Saginaw Central Foundry. Peek’s favorite president was John F. Kennedy “because he went toe to toe with the Russians,” and he voted once for Bill Clinton. But he voted for Trump. He liked Trump’s stands on immigration (“The immigrants coming over here, the illegal ones, when is our people gonna get fed?”), on China (“They keep loaning us money; they’re going to own the United States”), and on slapping a 35 percent tariff on auto imports. (“All of our businesses should be penalized if they move their plants overseas. He’s gonna put his foot down.”)

“He’s ahead of Clinton in my book,” Peek said. “He’s a businessman. If anybody’s gonna get us out of here and get us back on our feet like it should be, he’s the one.”

The Post's Dan Balz explores some of the factors behind President-elect Donald Trump's victory against his Democratic opponent, Hillary Clinton. (Bastien Inzaurralde/The Washington Post)

Trump promised to renegotiate the North American Free Trade Agreement, which was signed by Bill Clinton in 1993 over the objection of organized labor and has since been blamed for the loss of manufacturing jobs to Third World countries with lower wage and labor standards. Nowhere is that a sorer point than in Flint. In 1980, GM employed 80,000 in the Flint area; today, it employs 7,200. Flint’s decline began a decade before NAFTA, but the trade deal was seen as just another kick at the auto industry. In 1999, GM closed Buick City, a Flint assembly plant that once provided a living to 28,000 workers. Since its demolition, the site has gone the way of all Flint, with poplars and yarrow pushing through cracks in the asphalt.

“NAFTA was one of the biggest things that hurt the United States,” said Trump supporter Phil Hall, a salesman for a laser engraving company that does half its business with the auto industry. “NAFTA’s not something I agree with. GM’s big in this area. Since 1993, when that happened, there have been so many shutdowns of plants. I can’t tell you how many people have lost their jobs.”

The loss of manufacturing, and the economic power that goes with it, also resulted in demographic changes that made the Rust Belt states more inviting territory for Trump. Michiganders call the 2000s the “Lost Decade.” During those years, Michigan lost half its automaking jobs and fell to 35th in per capita income among states. It hemorrhaged residents, with many using their college degrees as tickets out: Michigan is 34th in proportion of college graduates. No one is moving in to replace them: Only Louisiana has a higher percentage of native-born residents. As Michigan has become older, less educated, less unionized, less urbanized and more insular, it has become more reactionary.

The brain drain from the old factory towns to the big cities contributed to Trump’s victory in the electoral college. He narrowly won the Rust Belt states, while Clinton posted a commanding victory in Illinois. The only industrial Midwestern state she won, it’s home to tens of thousands of young Michiganders, Wisconsinites, Ohioans and Pennsylvanians who fled their home towns for Chicago, the region’s cultural and financial capital, a city that’s winning in the 21st-century global economy at the expense of surrounding states. Had those college graduates found opportunities at home, they might have flipped their states to Clinton.

Even Michigan’s economic recovery since the Great Recession is not as good as it looks on paper: The unemployment rate of 4.5 percent is below the national average, but that’s not because there are more jobs — it’s because there are fewer workers. Health care has replaced manufacturing as the state’s No. 1 employment sector, and even the new automaking jobs start at $14 an hour, half of what they used to pay.

Will Trump be able to deliver on his promise to bring manufacturing back to the Rust Belt? Probably not. Most of the jobs that disappeared were lost to automation, not globalization. GM can now makes as many cars with 5,000 workers as it did with 25,000 in the 1960s. Others were lost to right-to-work states in the South. Attacking Mexican and Japanese workers for stealing American jobs, though, was also a way for Trump to combine economic nationalism with the ethno-nationalism that was such a big part of his appeal to white voters. (Although Ford may have helped his case when it announced in September that it’s moving all small-car production to Mexico.) But unlike Clinton, at least he had a message for people who feel left behind by globalization, and he was able to portray his opponent as a member of the political elite that has sold and hollowed them out.