On Friday night, Donald Trump and his red “Make America Great Again” baseball cap headed down to the Ladd-Peebles football stadium in Mobile, Alabama, where, in a long and rambling address, he regaled a crowd estimated by police and fire officials at around twenty thousand people. Among other subjects, he spoke about his big lead in the polls and joked about holding the 2016 election early. “I’d like to have the election tomorrow,” Trump said. “I don’t want to wait.” In another sign of the progress he is making, one of Alabama’s two Republican senators, Jeff Sessions, greeted Trump onstage and praised his tough stance on immigration.

To say that Trump is flying high would be an understatement. Not only is he crushing his Republican opponents in the polls, many of his critics in the media have thrown in the towel. Having dismissed his candidacy, poked fun at him, and portrayed him (with every justification) as a draft-dodging, racist, sexist huckster, the campaign press is now paying him the ultimate compliment and taking him seriously.

On the day of the rally, USA Today reported, with no evident irony, that Trump and his allies were plotting “a path to victory” in the G.O.P. primaries. The Washington Post said that Trump’s Republican rivals were being forced to adopt new strategies to ride out the “Trump tornado.” And a front-page story in the Boston Globe quoted Theda Skocpol, a professor of government and sociology at Harvard, who said, “What is happening with Trump is not a fluke. Yes, he is a great entertainer, but he is able to take advantage of a number of dynamics in American politics as they exist right now. This is an important moment.”

We shall see. Perhaps Skocpol is right, and Trump’s rise in the polls represents a deep and lasting political phenomenon. Perhaps, as I suggested a couple of weeks ago, it will wither away, like the candidacies of previous G.O.P. candidates who tickled the party’s base at roughly this stage of the campaign, such as Michele Bachmann and Herman Cain. In any case, setting aside Trump’s ultimate fate, his current position demands explanation. How is he doing it? Here are five vaguely plausible theories that I have seen put forward recently.

1. He**’****s a rich celebrity. “**Trump is the personification of a 21st-century America fascinated by the super rich and obsessed with celebrity,” James Pindell wrote in the Globe’s Friday story, citing interviews that he’d conducted with a number of historians. It’s not just that Trump’s ceaseless self-promotion and his role on “The Apprentice” have created a level of name recognition that his rivals can’t hope to match. With his status as a bona-fide celebrity, he can get his message out without having to worry about how it is intermediated by the political press, or about whether he is winning the “invisible primary” for the support of moneyed élites. Indeed, rather than being tested by the media, Trump is exploiting it mercilessly, especially the broadcast media.

Virtually everywhere you look on cable television there is an “exclusive” Trump interview. Since he draws much higher ratings than any other candidate, he knows the cable networks will keep inviting him on and giving him lengthy prime-time interviews, regardless of what he actually says. (This, surely, was the message of the Megyn Kelly dust-up.) The other candidates are forced to rely on occasional onscreen appearances (the debates, especially) and paid media (that is, advertising)—if they can afford it. The celebrity gulf puts them at an enormous disadvantage, which, for now at least, they are failing to surmount.

2. He can**’**t be bought. As the political success of Michael Bloomberg showed, the idea of a billionaire candidate who doesn’t need to kowtow to vested interests can have considerable appeal to American voters. Trump is a populist version of Bloomberg, and he has no compunctions about pointing out how beholden his opponents are to rich donors—who are largely guys like him. During the first televised G.O.P. debate, he was eager to say that he had contributed to the past campaigns of many of his rivals in the full expectation of receiving something in return. He also claimed, effectively, to have paid Hillary Clinton to appear at his wedding. This wasn’t just boasting: it was exploiting his unique position to the maximum.

Given the widespread belief among voters that most politicians have been hopelessly corrupted by the demands of fund-raising, Trump’s appeal isn’t necessarily confined to ultra-conservatives. Appearing on the Fox Business Network recently, Ralph Nader, the longtime crusader against money in politics, who has mounted two Presidential campaigns as an independent and two as the Green Party nominee, called Trump “a breath of fresh air.” “The two-party tyranny that blocks voter choices and dominates the political scene on behalf of big business needs to be broken up and Trump is the one to do it. It takes a billionaire,” he said. When even someone with Nader’s progressive credentials is making this argument, is it any wonder many other Americans find it attractive?

**3. G.O.P. voters like his policies. **When Trump accuses the Mexican government of sending its criminals to the United States and talks about deporting millions of undocumented workers en masse, many commentators, myself included, see him as engaging in misleading, impractical rabble-rousing. But, as I pointed out earlier this week, the demagoguery is working. Trump isn’t merely matching the more conservative Republican candidates on the immigration issue: he’s beating them. In arecent CNN poll, forty-four per cent of likely Republican voters picked Trump as the candidate who could best handle illegal immigration. (Jeb Bush came in second, with just twelve per cent.)

And immigration isn’t the sole issue on which Trump’s views are striking a chord. His tough-on-trade rhetoric resonates with G.O.P. voters, particularly middle-income and low-income white men. Indeed, a recent survey by Pew Research suggested that Republicans, as a group, are now more skeptical of trade agreements, such as the new Trans-Pacific Partnership, than the Democrats are. As Newsweek’s Matt Cooper pointed out in a prescient piece back in June, Trump largely has this issue to himself. Dependent as they are on corporate money, most Republican candidates—from Jeb Bush to Marco Rubio to Scott Walker to Ted Cruz—support trade agreements. Trump, by contrast, is free to take a populist line, which he is doing with great enthusiasm.

4. He**’****s the rider on a white horse. **On the radio a while back, I heard Pat Buchanan, who ran for President as a conservative insurgent twice in the nineteen-nineties, and again in 2000, compare Trump to Huey Long, the legendary Louisiana populist who assailed the rich, the corporations, and the metropolitan élites during the twenties and thirties. Like Long, Trump could speak to ordinary folk in a language that they could understand and relate to, Buchanan said. Long was a Democrat, of course, who espoused some policies—such as expanded public services, stricter regulation of business, and higher taxes on the rich—that Trump, in his current incarnation, might well dismiss as socialism. But there still might be something to the comparison. Long “spoke so directly to the people, and that is Donald Trump’s appeal,” Richard D. White, the author of “Kingfish: The Reign of Huey P. Long,” told the Boston Globe. “It is a purely personal relationship with his listeners. It is not based on factual issues.”