D ONALD TRUMP’S bigotry is such an established part of American public discourse that, in retrospect, one of the most febrile debates of 2016 looks naive. Back and forth it went, in the months before the election, as the Republican candidate issued a slur against a Mexican-American judge and for a while refused to disavow the endorsement of a former Ku Klux Klan Grand Wizard. Was Mr Trump mainly appealing to his supporters’ economic concerns—in spite of his chauvinism? Or was his race-baiting really the main draw?

The answer was in long before the president sent an especially offensive tweet this week, inviting four unnamed, but by inference non-white, Democratic congresswomen to “go back” to where they came from. It was settled before he refused to condemn the white supremacists of Charlottesville two years ago. The data from his 2016 election have been scrutinised, and the resulting analyses, detailed in books and papers, are in agreement. Political scientists find no clear economic rationale for Mr Trump’s victory.

Many states, such as Georgia and Maryland, which had moved away from the Democrats in the tough times of 2012, drifted back towards their candidate in the better ones of 2016. The millions of working-class whites whom Mr Trump recruited in rustbelt states did not buck that trend because of economic anxiety. They were no likelier to attribute their vote to it than they had been in 2012.

Rather, they were unified by nothing so much as antipathy to America’s growing diversity, and an attendant feeling that whites were losing ground. Both were expressed in hostility to immigration, immigrants and welfare spending (which many wrongly believed was being slurped up by migrants). No doubt these feelings were exacerbated by economic as well as cultural and sometimes personal fears: people are complicated and America is changing. These sentiments also predated Mr Trump. Yet they had not been such a big factor in voting decision-making until he made them so, by drawing out his audience’s inner grievances, like a magnet tugging at a metal splinter.

In their book “Identity Crisis”, John Sides, Michael Tesler and Lynn Vavreck describe the rationalisation such Trump supporters made as “racialised economics”. Only a small minority of voters hold old-style racist views on questions like black-white marriage, but a very large number believe that “undeserving groups are getting ahead while [my] group is left behind.” An earlier study by the Voter Study Group found hostility to immigrants to be the best predictor of a Trump voter. One by the Public Religion Research Institute found much the same. There has been no serious counter-argument. Mr Trump’s race card was the winning one.

Hence his inflammatory comment this week. For while the strength of the economy might appear to have given him a better electoral option, Mr Trump is intent on a repeat performance. There is no prospect of him toning down his rhetoric and pocketing the grateful majority of Americans who consider their personal finances to be “good” or “excellent”. The fact is, his behaviour and policies have already repelled a majority of voters. He wants the applause of his adoring base too much to change style. And his view that America is essentially a white country messed up by escapees from non-white ones appears to be irrepressible. Amid the continuing outrage his racist tweet stirred this week, there are three important things to say about this.

First, Mr Trump’s campaign will be more racially divisive than it was in 2016, when he won white voters by 20 percentage points. He was still feeling his way then, looking for praise from the New York Times and MSNBC ’s “Morning Joe”. And when he did ramp up the rhetoric he was criticised by Republican leaders. Even as late as Charlottesville, his inflammatory language was repudiated by elected Republicans, business leaders and senior aides including his daughter Ivanka and Gary Cohn. He has received nothing like such criticism this week. Moreover, his slur against the four congresswomen, Alexandria Ocasio-Cortez, Ilhan Omar, Rashida Tlaib and Ayanna Pressley—of whom only Ms Omar was born overseas and Ms Pressley is not even of recent migrant stock, merely black—came not from an eccentric candidate, but the president. If Mr Trump only repeated his divisive 2016 lines next year, they would carry more weight. And he will probably say worse, because he wants vindication, for himself and his reviled method. In the event of any setback, he is liable to double down.

It might work again, too, which is the second point. Mr Trump’s approval ratings are low, but resilient and competitive. Set aside the state-level polling, which is less positive for him, and he is only a few points short of the 46% he won in 2016. He need not be loved to make up the difference. He needs only to make his opponent more hated, which was his other ploy in 2016. This makes Democratic voters, whose early support for Joe Biden suggests a demand for a plain-vanilla moderate whom Mr Trump might find hard to demonise, more sensible than the party’s left-wing activists. They see in his vulnerability an opportunity to bring about a leftward shift that most Americans do not want. One plausible, though possibly too ingenious, theory for his attack on Ms Pressley and the rest, all of whom are left-wingers, is that he wanted to boost their prestige within the party. That may in any event be the result.

The Gipper took a different view

Democrats must resist Mr Trump setting their agenda in any way. They do not need revered anti-Trump warriors. They need to be able to rebuke his divisiveness smartly, keeping in mind their own reputation for hyperventilating. The bill introduced by Nancy Pelosi to censure his tweet passed that test. Its citation of a line from Ronald Reagan’s last presidential address, “If we ever closed the door to new Americans, our leadership in the world would soon be lost,” also spoke to the third point, which is the fundamental one. Mr Trump’s exclusionary vision of America is a travesty.■