Perhaps one day Donald Trump will be dragged out of the Oval Office, his tiny fingernails still dug deep into that fat oak desk. But Trumpland, the country that ignored the politicians and the pollsters and the pundits and gave him the White House in 2016, will outlast him; just as it emerged before he even thought of becoming a candidate. And for as long as it is here it will warp politics and destabilise the US.

I first stumbled upon Trumpland in 2012, a time when it bore no such name and appeared on no maps.

I was reporting in Pittsburgh that autumn, as Barack Obama crushed Mitt Romney while cruising to a second term as president. The big US broadsheets wrote up the Republicans as if they were an endangered species , while thirtysomethings in DC gazed deep into their spreadsheets or West Wing boxsets and foretold permanent Democratic majorities, gaily handed to them by a rainbow coalition of black, Latino and granola-chewing graduate voters.

Except I kept meeting people who lived in an alternative country. People like Mike Stout and his family. He’d worked for decades in the local steel mills and had been a fiery union leader. Now he spent every spare hour as a reincarnation of Woody Guthrie, carrying a guitar along with memories of standing in 2009 on Washington’s Mall to watch Obama’s inauguration, his breath freezing in the January air as the first black president was sworn in . “It was like a new world had opened up, just for an afternoon,” said his wife, Steffi.

But it was their far more subdued daughter, Maura, who troubled me. The steelworks of her dad’s day was long gone, so she’d gone to university and then spent two years hunting for a job. Now the 23-year-old was doing the accounts for a hotel, a non-graduate position paying $14 an hour, which Mike recalled as the same rate he’d earned at the steelworks in 1978 – without, of course, three decades of inflation. Among Maura’s year of about 500 graduates, she counted as one of the lucky ones.

“I don’t think I’m ever going to earn as much as my parents,” she said. “I don’t think my husband and I will ever have the same life as they did.”

We were in Pennsylvania, often painted as a land of blue-collar aristocracy and true-blue Democrats. But the political economy that had underpinned those ballot-box majorities was as rusted as an abandoned factory. Instead, Maura saw a political system that had failed her and her generation, in which every new day was worse than yesterday. And while the Stouts were leftwing, they had little in common with the party they supported. In their eyes, their home had been gutted of manufacturing and bilked by foreign trade deals, and appeared nowhere on the Clinton/Obama ideological map.

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Sure enough, four years later Pennsylvania became one of the rustbelt states that won Trump the White House.

Trumpland is not the same as the old Republican heartlands, even if they overlap. What the dealmaker saw more clearly than the Bushes, the Romneys and the McCains was that there was a new electoral coalition to be forged out of downwardly mobile white voters. “The people that have been ignored, neglected and abandoned,” he called them in Ohio in 2016. “I am your voice.”

And so he completed the great inversion of American politics: he turned the Republicans into a party whose future is tied to Trumpland. Even Trump’s rivals accept that. This summer, Texas senator Ted Cruz said: “The big lie in politics is that Republicans are the party of the rich and Democrats are the party of the poor. That just ain’t true. Today’s Republican party are Ohio steelworkers, today’s Republican party are single moms waiting tables…”

Whatever promises Trump made on the threshold of the White House, once inside he spent four years giving billions in tax cuts to rich people and trying to deprive millions of low-paid Americans of decent healthcare. For the poor whites who put him in power, Trump had nothing to offer apart from racism.

However grossly used by its leader, Trumpland is more than an imagined community. It has its own society and economics and politics ­– and they barely resemble the rest of the US. The 477 large and densely populated counties won by Biden account for 70% of America’s economy, according to new calculations by the Brookings Institute ; Trump’s base of 2,497 counties amount to just 29% (a further 1% is still to be counted). Brookings describes Trumpland as “whiter, less-educated and … situated in the nation’s struggling small towns and rural areas. Prosperity there remains out of reach for many.”

These people haven’t been left behind so much as cut loose from the US. Between 2010 and 2019, the US created nearly 16m new jobs but only 55,000 of them were suitable for those who left school at 16. Inequality this deep is not just economic, it is social and psychological. It is also lethal.

Two economists, Anne Case and Angus Deaton, have found that working-age white men and women without degrees are dying of drug overdoses, alcohol-related liver disease and suicide at unprecedented rates . In 2017 alone, they calculated that there were 158,000 of these “deaths of despair” ­– equal to “three fully loaded Boeing 737s falling out of the sky every day for a year”.

As Case and Deaton point out, African Americans have still harder lives. They die younger, and are less likely to go to college or get a job. Yet over decades their prospects are improving. For poor white Americans, on the other hand, the trends point straight down. The result, according to a new study by Andrew Oswald and former Bank of England rate-setter David Blanchflower, is that middle-aged, white American school leavers are now suffering an epidemic of “extreme mental distress”.

When you live in a zero-sum economy, in which you always lose while the other guy wins, then you too might subscribe to zero-sum politics – in which the Democrats aren’t just opponents but enemies, and democratic norms are there to be broken. “These people are hurting,” says Blanchflower. “And when you’re hurting you’ll buy what looks like medicine, even if it’s from a snake-oil merchant.”

This is where Biden’s kumbaya politics, all his pleas to Americans to join hands and sing, looks laughably hollow. You can’t drain the toxicity of Trumpism without tackling the toxic economics of Trumpland. And for as long as Trumpland exists, it will need a Trump. Even if the 45th president is turfed out, he will carry on issuing edicts and exercising power from the studio set of any TV station that will have him.

Eight years after meeting Mike Stout, I spoke to him this week. He didn’t have much good news for me. Maura lost her hotel position last year and is now working from home in the pandemic, phoning up people deep in debt and pressing them to repay their loans. His son, Mike, lost his job just a few weeks ago for the second time in five years, and now has no medical insurance while his wife has stage-4 cancer.

“They’ve been pushed off the shelf straight into the gutter,” he told me. “I don’t see any party out there willing to protect my children’s lives: not Democrat, not Republican.”

Aditya Chakrabortty is a Guardian columnist