When Ben Carson said he didn't think a Muslim should be president, Democrats — and even many Republicans — blanched. The Constitution! Demands were made that he apologize. He didn't.

Know who didn't think Carson did anything wrong? The vast majority of likely Iowa Republican caucus-goers. About 7 in 10 of them agree with Carson's sentiment on a Muslim president, according to new data from a Des Moines Register and Bloomberg. In addition, 8 in 10 agree with Carson's oft-repeated claim that the Affordable Care Act is the worst thing since slavery and that things might have turned out differently in Nazi Germany if the population had been armed.

The disconnect between the reaction of Washington's professional political class and that of actual GOP voters to Carson — and some of his more controversial comments — is telling.

Carson is, by far, the least understood candidate by the Republican establishment. Even more so than Donald Trump, the race's front-runner for the past three-plus months, establishment types don't "get" Carson's appeal. They see a slow- and low-talking first-time politician who often seems entirely out of his depth on issues — especially around foreign policy. Because they don't get Carson, they have long dismissed him as a serious candidate.

Here's the thing: The Washington political class doesn't choose the nominee for Republicans. And here's what rank-and-file Republicans see when they see Carson: a guy who embodies "not Washington" and "not political." Carson's profile — African American, world-renowned pediatric neurosurgeon, committed social conservative — appeals to lots and lots of Republicans in a place like Iowa because there is no prior offices held on his resume. That he hasn't ever run for anything before works for him not against him in the eyes of most early state voters.

If you think — and lots of people do — that Carson is simply a flash-in-the-plan candidate, I'd remind you of who won the Iowa caucuses in each of the last two contested Republican primaries: Mike Huckabee in 2008 and Rick Santorum in 2012. Both men were for and from the social conservative movement, and both positioned themselves as anti-establishment figures running, at least in part, against the Washington establishment. Sound familiar?

Carson has benefited from being lowly regarded or totally written off by those in his party who spend all of their time plotting how to win back the White House. He's been able to fly below the radar, building support where it matters — in early states. The new Register/Bloomberg poll should serve as a wake-up call for the establishment that Carson is not only very much a serious candidate but may be the best tuned to how the base of the party thinks of anyone in the field.

Ben Carson is for real.