Donald Trump speaks in South Carolina. Photograph by Alex Wong/Getty

Wednesday was the day when Washington woke up to the fact that Donald Trump could well be the Republican Presidential candidate, and that, perish the thought, he could even be America’s next President. The opinion polls had long been predicting an easy victory for Trump in the New Hampshire primary—but polls are one thing and actual votes are another. It’s a bit like the difference between hearing that a friend or family member has received a horrible medical prognosis and seeing the symptoms progress firsthand. The first is upsetting; the second is shattering.

“Armageddon for the GOP Establishment,” a headline at the National Review read. “Trump’s NH Rout Plunges GOP Establishment into Chaos,” said another one, at The Hill. “Donald Trump in Driver’s Seat on Way to Presidential Nomination,” the Weekly Standard claimed. All of this came just a week after writers for some of the same publications had been expressing the belief (or hope) that Trump’s second-place finish in the Iowa caucus meant that he had peaked.

There was a bit of support for that argument in the national opinion polls, but not much. On January 31st, the day before the Iowa caucus, the Huffington Post’s poll average showed Trump with 36.2 per cent of the Republican vote. On Sunday, February 7th, just before New Hampshire voted, his share was 35.2 per cent. One survey, from Public Policy Polling, did show him dropping back to twenty-five per cent, but six other polls showed him in the thirties.

If you ignore a bit of volatility here and there, Trump has held a big lead in the national polls since August: that’s seven months. For a long time, many commentators persisted in describing the Trump phenomenon as a temporary one. Today, the skeptics are thin on the ground. On Wednesday, one of the last of them, Nate Silver, of FiveThirtyEight, posted a column saying that Trump was now the legitimate front-runner.

As I pointed out back in December, one of the things that makes Trump a formidable candidate is that he’s tough to pigeonhole. He picks up support from almost all corners of the Republican Party—and from outside of it, too. In New Hampshire, the network exit poll indicated that he bested the rest of the field among Republicans and independents, men and women, conservatives and moderates, and all age groups except seniors. It is sometimes said that Trump’s support is confined to the poorly educated, but in the Granite State he also came out ahead among people who attended some college and among college graduates. The only educational demographic with which he didn’t finish first was voters with a postgraduate degree.

Why is Trump doing well? One explanation emphasizes his outsider image, his unorthodox style, and his willingness to say things that regular politicians won’t. Clearly, there is something to this theory. According to the New Hampshire exit poll, fully half of all voters in the Republican primary said that they wanted a political outsider as their candidate, and Trump got the support of nearly sixty per cent of this group.

When Trump makes offensive comments or insults his opponents and media critics, it seems only to confirm in the minds of many Republican and independent voters that he is an authentic anti-politician. Last weekend, Adam Gabbatt, a reporter for the Guardian, visited a biker bar in Seabrook, New Hampshire, where he found quite a few Trump supporters. “He’s bringing a point of view that isn’t common in politics,” one of the bikers said. “He’s self-funding so nobody can buy him,” said another.

To ascribe Trump’s rise entirely to his independent status and his political incorrectness would be a mistake, however. The message that he is delivering—a mélange of American nativism, conservative politics, and populist economics—is also falling on receptive ears. When Trump says that Washington has failed the country, he is merely restating a central tenet of modern conservatism. When he claims that free trade with China and other countries has undermined American prosperity and cost countless American jobs, many blue-collar workers think that sounds right. When he says that the influx of illegal immigrants, many of whom have crossed the Mexican border, is having a similar impact on American living standards, that strikes a chord, too. And when he says that something drastic has to be done to prevent the threat of further terrorist attacks by Islamist radicals, he is preaching to the converted.

According to the New Hampshire exit poll, nearly half of the voters in the Republican primary said that they were angry at the federal government, and seventy per cent said that they were worried about the economy. Four in ten said that they were in favor of deporting undocumented immigrants en masse. Six in ten said that they were “very” worried about terrorism. And fully two-thirds expressed support for Trump’s proposal to institute a temporary ban on Muslims entering the United States.

Figures like these, if they were to extend across the country, would have the makings of a winning coalition for Trump, because no other Republican candidate can match him for breadth. An establishment figure like Jeb Bush or John Kasich can’t hope to compete with him on incendiary issues like immigration and preventing Muslims from entering the country. A social conservative like Ted Cruz may match Trump’s rhetoric in these areas, or come close, but Cruz hasn’t got much of an economic message for embattled Reagan Democrats.

For now, at least, that leaves Trump in a strong position. He still has to demonstrate that he can extend his support beyond roughly a third of the G.O.P. electorate, but as long as his opposition remains divided, getting thirty or thirty-five per cent of the vote can take him a long way. On Wednesday evening, Predictwise, a Web site that combines information from the betting markets and the polls, was estimating the probability of Trump getting the G.O.P. nomination at forty-three per cent. With the polls showing him well ahead in Nevada and South Carolina, the next two states to vote, some would say that this estimate looks a bit low.