DONALD TRUMP has dominated the American right for nine years and yet, even after a decade of study, many observers still cannot fathom why. But voters are certainly not tired of Mr Trump. Even after the scandal and mayhem of his first term, culminating in his attempt to cling to power after losing the election in 2020, around half of the electorate, or some 75m Americans, will vote for him this time.

What accounts for his enduring strength? At first it was common on the left to point to racism, misogyny and xenophobia, sustained by misinformation and lies. Hillary Clinton infamously summarised this thesis. “To just be grossly generalistic, you could put half of Trump’s supporters into what I call the basket of deplorables,” she once said.

The early explanations from Mr Trump’s sympathisers could be equally simplistic and hysterical. In 2016 Michael Anton made the most prominent intellectual case for Mr Trump. He wrote that Americans needed to register a populist primal scream before their way of life was permanently extinguished, and called 2016 the “Flight 93 election” (referring to the plane hijacked on September 11th 2001 that crashed in a field in Pennsylvania after a passenger revolt). Mr Anton elaborated: “A Hillary Clinton presidency is Russian Roulette with a semi-auto. With Trump, at least you can spin the cylinder and take your chances.” Most Americans did not think 2016 was a Flight 93 election. In fact, 40% of eligible voters didn’t bother to express an opinion.

Calmer analysis is more helpful. Social scientists provide three kinds of explanation. Political scientists point out the importance of institutions; political economists put stress on material conditions; and political sociologists emphasise the cultural divide between elites and the self-described populus.

The first explanation, the political-science one, sees Mr Trump as a lucky beneficiary, or perhaps even a canny exploiter, of America’s peculiar political system. First-past-the-post voting, which awards elections to the candidate who commands a plurality, encourages a two-party duopoly. (When Mr Trump applied his talents to seek the nomination of the Reform Party in 2000, it did not end well.) Open primary elections have meant that rank-and-file members wield more power than party elites when selecting the presidential nominee. That allows a faction, as the Make America Great Again crowd could be called, to seize control of a major-party apparatus if it is successful enough.

Democrats had their own insurrectionary movements from the populist left in both 2016 and 2020, led by Bernie Sanders and then by Elizabeth Warren. But neither of them managed to capture the consistent 25-35% of primary voters that Mr Trump did in the early Republican primaries in 2016. Were European-style multiparty democracy to be transplanted to America, a Trump-led MAGA party might draw a lot of support without attracting a majority—like the hard-right Alternative for Germany.

Once in charge of the party, the two-party system works in favour of the rebellious faction, forcing co-partisans to make their peace with the new leadership. This explains a lot of Mr Trump’s support now. But the political-systems approach is less satisfying as an explanation for why his hold is so enduring, making him the first person to win a major party’s nomination three times in a row since Franklin Roosevelt.

Political economy—explanation number two—could throw light on part of this longevity. The American economy boomed during Mr Trump’s first term in office, up until the covid-19 pandemic. Although voters did not approve of Mr Trump’s conduct in office, and especially on January 6th 2021, when his supporters violently breached the Capitol, their anger over inflation and pessimism over the economy are pushing them to rebuke the incumbent Democrats, to the benefit of Mr Trump.

Evidence from outside America suggests there is a lot to this. Voters are in an anti-incumbent mood everywhere, rejecting the ruling parties in Britain, France, India and Japan (and presumably next year in Canada and Germany). But the idea that the economy is making people cross does not fit with what’s actually happening in America. The gap in output per person between Canada, western Europe and Japan on one side and America on the other has doubled since 1990. America’s economy is the envy of the world, with fast increases in real wages for the poorest workers. If inequality is the cause, that is hard to square with data showing wages rising in “left-behind” places and no increase in income inequality in the past decade.

That leaves a third genre of explanation: political sociology. Even though American politics has remained almost perfectly divided over the past decade, it has not been static. Voters are less divided by income or race than before; instead a striking new dividing line is educational class. Democrats increasingly attract the support of the professional, suburban managerial class who find Mr Trump repulsive and unfit for office; the working classes, including an increasing share of the non-white working class, admire that Mr Trump has made the right enemies, talks like them, talks to them, and promises them a future in which they receive dignity and their just financial desserts—even if they know that these promises are unlikely to be kept.

Visiting an area in North Carolina hit hard by flooding a few weeks ago, Mr Trump promised that under his rule every property that had been destroyed would be rebuilt, and more beautifully than before. Never mind that some of them are in areas prone to flooding and so will not be rebuilt. It was what people wanted to hear. One speaker who welcomed Mr Trump described his visit as the shot in the arm of hope that people needed, and said his visit guaranteed that people there would not be forgotten. To use the language of pop psychology, Mr Trump makes a lot of Americans feel seen. That he is happy to dress up in the uniform of a McDonald’s worker or a garbage-truck guy, despite being worth several billion dollars, helps too. Kamala Harris, who actually worked at McDonalds, seems to cringe at such stuff.

The realignment according to educational qualifications means that the most serious divide in America is over culture rather than money. Under Mr Trump, the Republican Party looks increasingly left-labour in its economics, advocating protectionism, working-class tax giveaways and preservation of the existing entitlement system. To many Americans without a college degree, Democrats no longer talk to them but down to them. That is why, despite being showered with dollars from the federal government under President Joe Biden, members of America’s industrial unions are moving towards Mr Trump this year. And it is why the Trump campaign seized on remarks by a befuddled Mr Biden a few days ago, in which he appeared to call Trump supporters “garbage”. “See: Democrats still think you are deplorables,” was their message.

Democrats—and a good number of former members of the Republican elite—genuinely wonder how it is that Mr Trump’s supporters so quickly dismiss his efforts to overturn a democratic election, or his poor record of achievement on policy in office, or the undermining of abortion rights which he engineered. Mr Trump’s supporters see these criticisms as overhyped. And they see them as hypocritical, pointing out that the legal system has in fact been weaponised against Mr Trump in a way that he merely threatens.

Culture means Democrats and Republicans live in different countries. Tens of millions of Trump voters (mistakenly) believe America is in a recession. They think Democrats brought on inflation when they managed the economy, which boomed under Trumponomics. They observe that there were no new wars launched when Mr Trump was in the White House. Under Mr Biden’s watch, there are security crises in the Middle East and Ukraine. Trumpism is a simple heuristic, just as Trump-loathing is. It could be powerful enough to take him back to the White House.