Dr. Ben Carson, the Republican right’s favorite African-American neurosurgeon, often says that President Obama’s health care law is the worst thing since slavery.

But in my recent interview with the good doctor—who is riding high in the presidential preliminaries, having come in a close second to Sen. Ted Cruz this past weekend in the Republican Leadership Conference’s much-ballyhooed straw poll—he upped the ante.

He claimed that Obamacare has been even more damaging to the United States than the terrorist attacks of 9/11.

“You said Obamacare was the worst thing that has happened to this coutry since slavery. Why do you think it was worse than 9/11?” I asked him.

“Because 9/11 is an isolated incident,” he answered.

We were sitting in the Sirius XM Radio studio in Manhattan, where Carson was going on the air with conservative host Armstrong Williams to promote his just-published political manifesto, One Nation: What We Can All Do To Save America’s Future, which is No. 1 on The New York Times Hardcover Nonfiction Bestseller List.

Williams, who is acting as the doctor’s business manager, frequently interrupted as I attempted to explore Carson’s unusual assertion during breaks in the program. Our exchange went something like this:

Me: “Who do you think caused families more pain—Obamacare or Osama bin Laden?”

Carson: “Let me explain.”

Williams: “Let him answer the question!”

Carson: “Things that are isolated issues as opposed to things that fundamentally change the United States of America and shift power from the people to the government. That is a huge shift.”

Me: “Right. But what do you think caused specific families more pain—Obamacare or Osama?”

Carson: “You have to take a long term.”

Me: “You’re not answering the question.”

Carson: “Will you listen? You have to take a long-term look at the ascent of something that fundamentally changes the power structure of America. You have to be someone who reads. Who is well-read. I want you to go back tonight. I want you to pull out what Saul Alinsky says about health care under the control of the government.”

At which point Williams cut the interview short and canceled a promised post-show session at Penn Station where Carson, a retired pediatric brain surgeon at Johns Hopkins Hospital, would be waiting for his train back to Baltimore.

The only other question I was given time to pose came before the 9/11 dustup, when I asked Carson, who self-identifies as deeply religious, if he’s ever doubted or been angry with God.

Yes, indeed, he indicated, recounting an incident in which the Lord apparently subjected him to Job-like tortures over a problem involving residential real estate. After buying a new house, he just couldn’t unload the old one. “My house was on the market for five years. And I said, ‘I pay my tithes. I am faithful. I try to help people. So why is this happening to me?’ ” Carson told me.

“And [then] I found out about the ‘1031 Exchange’ [named for a tax code provision] where if you sell a piece of property and you make a very, very large profit on it, you don’t have to pay huge taxes on it if you can roll it over into another property of higher value.”

Carson’s story went on in this disjointed fashion, and didn’t seem particularly illuminating, except to suggest that it definitely wasn’t an ordinary crisis of faith and the Almighty must be a savvy adviser on the Internal Revenue Code.

Needless to say, the doctor’s eccentric claim concerning the relative evils if Obamacare and jetliners crashing into the World Trade Center and the Pentagon didn’t go over well with visitors to the new 9/11 Memorial. It’s a shrine to more than 3,000 people—Americans and foreign nationals—who were killed on Sept. 11, 2001, inciting two costly wars in which thousands more Americans died.

“Who is he? Some kind of crackpot?” asked an Irvine, Calif., man who declined to provide his name.

Yet Carson is undoubtedly a powerful new force in the GOP cosmology.

Williams had invited me to meet his friend, saying they wished to respond to my first article, on Carson’s glib and troublesome ideology, in The Daily Beast two weeks ago. Williams said they especially objected to the headline calling Carson “The Conservatives’ Great Black Hope.”

Oddly, however, when Williams asked his guest to respond on the air, Carson answered: “I pretty much don’t respond… I recognize that there is a large segment of society that sees everything through the prism of race. I never have.”

“Dr. Carson is not about race,” Williams insisted later, notwithstanding that the doctor famously told right-wing talk jock Mark Levin that white liberals are “the most racist people there are. Because they put you in a little category, a box: ‘You have to think this way, how could you dare come off the plantation?’ ” Williams claimed that Carson’s repeated comparisons of Obamacare to the enslavement of blacks in the South is actually about freedom, not race.

After reading Carson’s book, it’s difficult to escape the conclusion that some of his ideas are a noxious mix of ignorance and certitude—a dead-serious version of Stephen Colbert—while some others are just plain disturbing. On Page 94 of One Nation, for instance, Carson takes refuge in the right-wing loon canard that big-government liberalism—a phenomenon that, as a conservative, I’m no fan of myself—is a slippery slope to Nazism.

“Throughout history many societies have failed to push back and have allowed an overly aggressive government to expand and dominate their lives,” Carson writes. “Nazi Germany is a perfect example of such a society…[Adolf Hitler’s] regime may have started out innocently enough, but because the people did not oppose a progressively overreaching government, the entire world suffered a great Holocaust.”

There’s way too much here to unpack for this space, so let me just focus on Carson’s jaw-dropping claim that the Third Reich “may have started out innocently enough.” Really? Has the doctor never heard of Mein Kampf?

Carson is currently in the midst of a 29-city, Sarah Palin-esque bus tour that will undoubtedly stoke interest in a 2016 candidacy. His showing in the straw poll last weekend—29.38 percent to Cruz’s 30.33 percent—left “serious” prospective candidates such as Rand Paul, Mike Huckabee, Rick Perry, Marco Rubio, and Jeb Bush eating the doctor’s dust.

The mainstream media largely ignored Carson’s showing at the leadership conference in New Orleans, giving the headlines to Cruz, maybe because it was hard to fit into conventional wisdom, particularly since, unlike Cruz, Carson didn’t even attend.

If the media are baffled, they’re not the only ones. “How is that possible when I am not there?” Carson asked this week, according to Williams. “I am not doing anything to earn this.”

A year and seven months before the first Republican primary, it is already shaping up as a strange campaign.