The indomitable Donald Trump continues to soldier on, undefeated in his battle to win his party’s nomination at its convention in Cleveland in the third week of July.

Last Tuesday, in what was dubbed unofficially the “other Super Tuesday,” after the official one on March 1, he effortlessly won the primaries in Florida, North Carolina and Illinois, amassing an advantage in delegate counts beyond the 1237 he needs to run for election as president of the US against (one assumes) Hillary Clinton in the general election.

Trump has been criticized by the Republican establishment for the crude tone of his candidacy and the locker room vulgarities he has uttered at his rallies, but the billionaire remains unconcerned, even defiant, calling himself the candidate of the “angry and disaffected.”

At a rally in Florida, for example, he hollered: “There’s great anger. Believe me, there’s great anger.” And leaders of that establishment are helpless at impeding, let alone blocking, his inexorable march. The two remaining contenders, Ted Cruz, who is even more reviled by these leaders, and John Kasick, who has won primaries only in Ohio, are by now no threat. Moreover, the chance of a brokered convention, alternately referred to as a contested convention, appears mockingly remote.

Who are these “angry and disaffected” Americans who have turned to Trump, an improbable presidential candidate who was able nevertheless to dispatch, with impressive ease, fellow presidential aspirant Scott Walker in September last year, cripple the well-funded campaign of the well-pedigreed Jeb Bush, send Chris Christie packing (hopefully to a gym) last month, and destroy Marco Rubio, in Rubio’s own home state in Florida, last Tuesday?

They are not, or are not all, as a glimpse of them at Trump’s rallies would at first blush suggest, under-educated, blue-collar, uninformed rednecks. A great many of them are middle-class, middle-aged, middle-brow folks who yearn, albeit unrealistically, for a return to the time in the 1950s and early 1960s when Wasps reigned supreme, Doris Day and Rock Hudson bantered inanely and flirted innocently in “Pillow Talk,” and no one told you on the phone to “press 3 for English,” essentially folks with a nostalgia for the absolutes of the past who refuse to believe that there is no return to the status quo ante and that America is a nation of immigrants in constant transformation demographically, and thus responsive to shifts in its cultural sensibility, social values and lifestyle.

As David Frum, the conservative Canadian-American political commentator and former speech writer for President Bush, wrote in “The Great Republican Revolt,” an article published in Atlantic magazine last month: “White middle-Americans express heavy mistrust of every institution in American society: Not only government, but corporations, unions, even the political party they typically vote for ... They are angry. And when Donald Trump came along, they were the people who told the pollsters, ‘That’s my guy.’ They are not necessarily super-conservative. They often don’t think in ideological terms. But they do strongly feel that life in this country used to be better for people like them, and they want that older country back.”

In fact, these voters are part of a populist insurrection — one that is not by any means passing unnoticed —that has swept far and wide across the Euro-American world, an insurrection by folks who have founded movements to voice their discontent, at times in measured, center right rhetoric, such as Nigel Farage’s UK Independence Party, a Eurosceptic group that wants Britons to exist the EU, and at other times in strident, neo-fascist lingo, such as Marine le Pen’s National Front in France, that wants strict, draconian immigration enforcement.

In America, no less than in Europe, national identity has become imbued with race, religion, ethnicity and parochial self-definitions. And beyond identity is the suspicion by Trump supporters that they have been short-changed economically. America may have recovered from the recession in the summer of 2009, they will tell you, but they have not shared in that recovery — and they resort to nativist rhetoric to express their malaise. Trump has simply made sure that his own rhetoric hooked on to theirs. And it is no surprise then that he has won their votes, their hearts and their devotion.

How it will all pan out when Trump locks horns with Clinton in November will represent an event of great interest not only to Americans but, given America’s leading role in the global dialogue of cultures, to other people around the world as well.