So, 58 percent of Republicans either think Barack Obama was not born in America, or aren't sure. As Politico's Glenn Thrush explains:

That means a majority of Republicans polled either don't know about -- or don't believe the seemingly incontrovertible evidence Obama's camp has presented over and over and over that he was born in Hawaii in '61.

Now, where on earth would people get the idea that Barack Obama might not have been born in Hawaii?

Obama has, after all, proven that he was. The state of Hawaii and its Republican governor have said that he was born there. Prominent conservatives like Joe Scarborough have made clear that Obama was born in the US. Even many of the nuttier media conservatives -- Ann Coulter, David Horowitz, Michelle Malkin -- have dismissed the Birther conspiracy theories.

But not everyone has been clear that there's nothing to this nonsense. Lou Dobbs promotes this insanity, pretending that Obama has not proven his citizenship. And CNN -- the “most trusted name in news” stands by him as he does so.

CNN may not realize this yet, but this is not a game. Lou Dobbs' promotion of ludicrous conspiracy theories is not amusing, and it is not harmless.

A frighteningly large number of people believe the patently, provably, obviously, clearly false claims that Barack Obama was not born in America. At best, that does significant damage to the public's ability to make informed decisions, without which democracy cannot properly function.

That's bad enough, but what happens when some nutcase decides he's going to do something about this foreign interloper illegally sitting in the White House?

The bottom line is that millions of Americans hold the false belief that Barack Obama's American citizenship has not been proved -- and CNN's Lou Dobbs is the most prominent media figure who has given that theory credence. The linkage between those two facts is clear -- unless CNN wants to argue that its reporting has no effects whatsoever on the beliefs of its viewers.