On the Sunday evening before Election Day, as part of his eleventh-hour barnstorming tour, Donald Trump touched down on some of the most famously contentious political turf in the country. Macomb County—the big, overwhelmingly white, working-class suburb of Detroit—is currently embroiled in a lawsuit for blocking the construction of a mosque. It’s also home to the original “Reagan Democrat,” that once-prosperous union voter who abandoned the Democratic Party in the 1980s and upended the political map. The perfect place, in other words, for Trump to make a last-ditch appeal for support.

Unlike white voters down South, working-class voters across the Rust Belt ranged all over the electoral landscape after Reagan. Macomb backed Bill Clinton in the 1990s and voted twice for Barack Obama. But Hillary Clinton took Macomb’s support largely for granted, leaving working-class whites in the county—which lost more than half of its manufacturing jobs between 2000 and 2010—an easy target for Trump.

Trump was running late for his rally, but after Ted Nugent played for the 8,000 white voters in the Sterling Heights Amphitheater, they entertained themselves with chants of “CNN sucks!” and “Lock her up!” When the man himself arrived, he issued what would soon become a famous prophecy, the political equivalent of Babe Ruth’s home-run point or Joe Namath’s “guarantee” of a Super Bowl victory. The polls were either wrong or rigged, Trump thundered. “We’re going to go on Tuesday, and we’re going to win like they’ve never seen,” he vowed. “This is going to be Brexit-plus.”

When that expert-defying prediction came true, it looked like the Reagan Democrats had once again transformed the political map. Nationwide, Trump won working-class whites by a margin of more than two to one, outpacing Reagan’s historic highs in 1984. Across the Rust Belt, longtime Democratic strongholds flipped red. In Ohio, Trump won the blue-collar bastion of Trumbull County by six points, converting voters who had supported Obama by 22 points in 2012. In Pennsylvania, Trump narrowly lost working-class Lackawanna County, where Hillary Clinton’s father was born—but still pocketed 13,000 more votes than Mitt Romney did. And in Macomb itself, Trump won by double digits, capturing 33,000 more voters than Romney—nearly three times his razor-thin margin of victory statewide. Riding the blue-collar wave, Trump won Michigan, Wisconsin, and Pennsylvania—and his Electoral College margin of victory—by a total of just 110,000 votes.

The implication seemed clear: The election had been decided by working-class whites. It was “the revenge of the deplorables,Bloomberg View proclaimed. Shocked Democrats immediately descended into finger pointing. Some blamed Clinton, a Washington insider running in an election fueled by populist anger. “The Democratic establishment is finished,” wrote Slate’s Jim Newell. “What a joke.” Others called on the party to rethink its entire strategy. Within days, The Washington Post reported, Sanders and other liberal activists were pushing to transform the Democratic Party into “an advocate for working-class voters.” Sanders supporters pointed to his victories over Clinton in Michigan and Wisconsin—Trump-style upsets fueled by heavy white majorities—as evidence that the party needed a whole new focus on blue-collar voters screwed by free trade and Wall Street.

There’s no question that without the record support of working-class whites, Trump would not have eked out his narrow wins in the Rust Belt—or in the Electoral College. But the truth is, 2016 did not mark a fundamental shift in the American electorate—and revamping the Democratic Party’s entire political strategy would be an enormous mistake. “This was an extreme election,” says William Frey, a demographer at the Brookings Institution. “All the stars and moon were aligned the same way for the Republicans.” In fact, a closer look at what happened in Macomb County and elsewhere in the Rust Belt reveals that 2016 may well represent what demographer Ruy Teixeira calls “the last stand of America’s white working class”—the final time that blue-collar whites will determine a national election.

It’s all in the numbers. Since 1980, working-class whites have seen their share of the electorate plunge by about 30 percent—and it will continue to decline another two to three points every four years. Meanwhile, the “rising majority” that favors Democrats—single and professional women, people of color, and millennials—will continue to grow. Overall, the minority share of the electorate, which stood at just 23 percent in 2000, will soar to 40 percent by 2032. Over the past four years alone, the clout of Asian American and Latino voters has jumped by more than 16 percent.

Even with Clinton’s shortcomings, Democrats fared well in states with the fastest-changing demographics. Clinton won Virginia and Colorado handily, and Nevada more narrowly. She also cut into the GOP’s victory margins from 2012 in Arizona, Texas, and Georgia. But in North Carolina and Florida—two battleground states expected to trend blue in the future—Democrats fell short of expectations. “Unfortunately for Democrats, not every state looks like Virginia or Colorado,” says Kyle Kondik, who analyzes elections for the Center for Politics at the University of Virginia.

The trend is so strong that no level of turnout among working-class whites will stem the demographic tide. “The racial composition of the electorate will continue to shift dramatically over the next four elections,” says Teixeira, co-author of The Emerging Democratic Majority. “Even with the astronomically high support for Trump among the white working class and the relatively weak minority support for Clinton, projected demographic shifts will still produce a very different outcome in 2020.” Even if blue-collar strongholds like Macomb County swing redder next time, the GOP will still come up short.

The turnout in November suggests even worse news for Republicans. Despite the image of a “Trump surge,” the white share of the electorate was the lowest in history, at just 69 percent. Trump won evangelical voters by a record-smashing 65 points, and he even won college-educated whites—but by 10 points less than Romney. The real problem for Democrats wasn’t that whites showed up on Election Day—it’s that they broke so strongly for Trump, while many minority voters stayed home. In Michigan’s Genesee County, which includes majority-black Flint, Clinton narrowly won—but garnered 26,000 fewer votes than Obama did in 2012.

Such numbers suggest that working-class whites don’t hold the key to future victories for Republicans, let alone Democrats. To forge a winning coalition going forward, the GOP will need to do everything it can to buttress its support among white professionals and evangelicals—by overturning Roe v. Wade, for instance, and passing tax cuts for the wealthy. Republicans will also intensify efforts to suppress minority turnout by passing voting restrictions at the state level. “Sooner or later, Republicans are going to reach out to minority groups,” says Frey. “But Trump’s victory may hold them back, and make them think they can keep riding the white vote for longer.”

That thinking will likely be short-lived. The GOP, says Teixeira, is “clearly riding on demographic borrowed time.” In the long run, Trump’s coalition of the aggrieved may have as little staying power as the agrarian populists of the 1880s, whose rural base was ultimately overwhelmed by urbanization. Ironically, if Republicans continue to ignore America’s new majority—women, young voters, and people of color—their only sure path to the White House will be the one Trump denounced: rigging the election.