As someone who has never run for office before and who seems to neither know nor care much about the substance of what a president does, Ben Carson's appeal among Republican voters can be a little hard to discern. He's outwardly devout, appealing to evangelical voters — but so are many of the other presidential hopefuls (Mike Huckabee is even an actual Baptist minister). He has an inspiring life story, which is great, but that doesn't necessarily make you choose him over other candidates. He's an "outsider," but so are lots of other contenders (even some who currently serve in Congress claim that mantle).

But there's one thing that distinguishes him from other candidates that hasn't gotten a lot of attention, and may have something to do with the fact that Carson is firmly in second place in the GOP race: only he fully embraces an apocalyptic vision of the American nightmare that is upon us. More than anyone else, he represents a particular fringe faction of the conservative movement, one that saw its prominence increase during the early years of the Obama administration, but as of late has been fading somewhat.

If you listen to Carson, you won't have to wait long before he references some bizarre conspiracy theory or says something indicating that he thinks everything is about to turn to hell. This a marked contrast with Donald Trump, for instance, who insists that America is already a dump, where our leaders are idiots, China stole all our jobs, and we never win anything. Carson, on the other hand, says that the real cataclysm isn't here yet, but it's on its way.

So this week, Carson asserted at an appearance in New Hampshire that a fascist takeover could happen here in America, and "political correctness" would be the first step. "If you go back and look at the history of the world, tyranny and despotism and how it starts, it has a lot to do with control of thought and control of speech." Later he elaborated, "If people don't speak up for what they believe, then other people will change things without them having a voice. Hitler changed things there and nobody protested. Nobody provided any opposition to him."

Carson talks a lot about "political correctness," which usually consists of someone criticizing him for something he said. Like many on the right, he seems not to grasp that free speech means you have the right to say whatever you want, but it also means that I have the right to call you a jerk for saying what you said. And when I do so, no one has violated your rights, much less tossed you in jail. But he sees a direct line between criticism from other citizens and government suppression of speech, which leads, inevitably, to Hitler.

Carson has also suggested in the past that there might not be an election at all in 2016, because by then Barack Obama would have sent America spiraling downward into anarchy. He was hardly alone — for years, it was common on the right to hear that Obama would seize permanent power in some kind of coup and cancel the election. You'll often hear Carson drop references to Saul Alinsky into his talks — Alinsky was a radical theorist who supposedly laid out the blueprint for socialist revolution that Barack Obama is following — and he also regularly tells audiences to read the work of W. Cleon Skousen, a Cold War-era conspiracy theorist even many conservatives consider a loon.

You know who else tells his audiences to read Skousen? Glenn Beck. While his days of appearing on magazine covers are a few years behind him, Beck still has a sizeable audience drawn to his fevered scribblings on chalkboards and warnings of the coming collapse of America; after taking in one of his rants, they can hear ads for all their doomsday prepper needs. So long as you've got internet access in your bunker, you're ready to go.

Though Beck condemned Carson earlier this year for saying that the fact that men have sex in prison is proof that homosexuality is a choice, much of what Carson has to say seems to come straight from Beck's various programs, including the recent trouble Carson has been in for his assertion that no Muslim should be president unless he disavows his religion, because Islam itself is incompatible with the Constitution. That could have come right from Beck's current best-seller, It IS About Islam: Exposing the Truth About ISIS, Al Qaeda, Iran, and the Caliphate.

Whenever there's a Democrat in the White House, a certain brand of anti-government right-wing extremism crops up, whether it was the black helicopter-spotting "patriot" movement in Bill Clinton's time or the John Birch Society in the 1960s. But Barack Obama's version was particularly convinced not only that the breakdown of society was on its way, but that the president was intentionally engineering it. You can understand the appeal of that belief — it says that only you are smart enough to see what others don't, that you're living in momentous, dramatic times, and that you'll be a capable, courageous hero when everything disintegrates (and you'll get to shoot people, too).

But we haven't heard quite as much lately from the doomsday crowd as we did a few years ago. Maybe it's because the economy is slowly but surely recovering, or maybe it's the fact that Obama's tenure is heading toward its end with little indication that he's actually going to dissolve Congress, throw the Supreme Court in prison, and declare himself emperor-for-life.

That isn't to say that the conspiracy theorists are gone altogether; just look at how worked up they got about Jade Helm 15. But they seem to have slunk back away from the center of the conservative movement, at least to the point where Republican presidential candidates feel no need to court them.

Except for one, Ben Carson. By all indications, he's doing it not by way of some clever political strategem, but because he actually believes what he says. Which is the most disturbing thing of all.