Despite calling John McCain “a loser” for his time as a prisoner of war in Vietnam, characterizing many Mexican immigrants as rapists and criminals, and calling Megan Kelly “a lightweight” (among other things), Donald Trump carries on with his strange combination of masculine bravado and a simple narrative that Americans have been cheated out of prosperity by their “stupid” leaders.

Donald Trump has led every poll of Republican and Republican-leaning voters on Real Clear Politics since July 12th – and by ever-increasing margins.

Who are these people, comprising about a quarter of Republicans, who have fallen for Trump?

The conventional wisdom, as the New York Times puts it, is that Trump “draw[s] support from voters looking to rage against the political establishment.”

But it doesn’t seem like this is pure protest à la voting for Iceland’s “Best Party”, which campaigned (and won) Reykjavik’s 2010 municipal elections promising free towels at all public swimming pools. Many people really think Trump has what it takes to make Washington work for them.

A CNN/ORC poll released last Wednesday found Trump leading the field on a variety of important issues, capturing a plurality of Iowa Republicans on the economy, immigration, terrorism, and ability to change Washington. On the economy, Trump gained the support of more than 35% of respondents. Trailing in second place was Carly Fiorina, former Hewlett Packard CEO, with just 10%.

As Trump has said before: “I went to the Wharton School of Business. I’m like, a really smart person.”

Of course, one does get the impression from interviews of Trump supporters that they are frustrated and probably resentful.

One illustration of this is among blue-collar workers hurt by outsourcing and layoffs – the losers of globalization and technological changes. A Washington Post article following Trump’s campaign in Flint, Michigan portrays him as “the candidate talking most directly about the loss of manufacturing jobs to foreign countries.” Trump connects to these voters through a combination of nostalgia and assertive calls to restore American jobs.

In contrast to a Republican establishment that sees the outsourcing of jobs in towns like Flint as a natural and efficient product of free trade, and Democratic leaders who are equivocal about it – often voicing skepticism of free-trade and criticizing outsourcing but also creating deals like NAFTA and the Trans-Pacific Partnership – Trump bills himself as “the super-president personally yanking jobs back into the United States.”

It’s not hard to see which message resonates most with these voters. Trump taps into resentment from people who feel like they have been cheated out of the American dream – whether by the Chinese cheating by manipulating their currency or the Mexicans cheating our immigration laws. This nationalistic populism, many observers have noted, parallels similar movements in European politics. “In Europe, Donald would have seats in Parliament,” writes The Economist.

All together, Trump brews “a heaping glass full of the frustration cocktail Americans have been served over the past decade: wars that don’t end, a Congress that doesn’t work, [and] paychecks that don’t grow…” He speaks to Americans who are mad that Wall Street got bailed but Main Street didn’t and Americans who are mad that Washington just doesn’t listen. He is an unlikely populist hero, given his unabashed wealth and arrogance, but the simple way Trump talks about outsourcing, China, and bailouts is probably closer to how many ordinary Americans think about these issues than the more nuanced rhetoric of other politicans.

Many people drink it up, clearly. But there is still some disagreement about who they are. Frank Rich of New York Magazine credits Trump’s success to giving voice to the thoughts of the Republican base, saying “his xenophobia and misogyny have long been orthodoxy among the [Republican] party’s base… The difference between Trump and his cohort is that he shouts his party’s ugliest views at the top of his lungs and without apology rather than sugarcoating them…”

By contrast, Joseph W. McQuaid, publisher of the Union Leader newspaper in New Hampshire, said in an email to the New York Times: “Trump isn’t and wasn’t going to get the conservative vote… Trump isn’t philosophically a conservative, and that will come out.”

He continues: “Trump’s base is more the people who used to have season tickets to the Roman Colosseum. Not sure that they vote in great numbers, but they like blood sport.”

So who is right? Does Trump’s support come from the center or periphery of the Republican fold?

The data points to the latter. According to a Washington Post/ABC Poll, Trump’s supporters tend to be less-educated and less-conservative than the average Republican. While Trump is the top choice of 32% of Republicans without a college degree, he gets support from just 8% of college-educated Republicans. Interestingly, Trump does much better among “liberal” and “moderate” Republicans than conservative Republicans. Very conservative Republicans prefer Scott Walker to Trump, by a margin of 25 to 17 percent – contradicting the idea that Trump “reflects a disturbing new far-right tilt in the GOP.” His support is greater among those under 50 and among people earning less than $50,000 annually.

(Trump’s supporters are of course white: 70% of blacks had an unfavorable view of Trump in a recent Gallup Poll, despite Trump’s claims that he gets along well with “the blacks.” Perhaps more surprisingly, Trump gets about equal support from men and women, according to the WP/ABC Poll.)

This makes sense: Trump is disliked by so many high-brow conservatives (Erik Erikson, Bill Kristol, George Will, Megan Kelly, etc) that he is clearly not the choice of party elites or conservative intellectuals – people who devote their lives to studying politics and developing a coherent ideology. Trump said in the first Republican debate that socialized healthcare “works in Canada” and “works incredibly well in Scotland” – not exactly mainline Republican thinking.

In short, the typified Trump supporter is a low-information, ideologically moderate or heterodox, disaffected, blue-collar white person – the sort of person who is “least likely to know or care about [Trump’s] lack of consistency with the standard party line.”

As Patrick Ruffini, a Republican strategist and political analyst, puts it: “Trump outperforms the most amongst the groups least likely to vote in a Republican primary.” Partisans, activists, and ideologues prefer someone more consistently conservative, like Scott Walker. But if Trump did run as an independent candidate, it’s likely that the same people who say they’d vote for him in the Republican primary now would vote for him then.

This is politics, not physics, so of course it could change. Indeed, rather than becoming narrower, Trump’s appeal seems to be gaining new ground. As Harry Enten of the New York Times’ 538 reports: according to one set of polls, just 20% of Republicans rated Mr. Trump favorably in June. Now, in early August, 52% do.

Where it stops, no one quite knows. Political analysts like Nate Silver reassure us that, once some candidates drop out and Republicans coalesce around a smaller field, Trump will lose. But Mr. Trump continues to defy conventional wisdom – and enrage in equal measure.