With media figures fixated on false claims that President Obama was not born in the United States, Sean Hannity made perfectly clear where the blame lies: with the "Obama mania media's bias," which “would have you believe that the only thing conservatives talk about is the birth certificate.”

An hour later, Greta Van Susteren and Donald Trump talked at length about the birth certificate on Fox News, and Trump concluded that “a lot of Republicans” agree with his birtherism.

Indeed, according to a recent New York Times/CBS News poll, 45 percent of Republicans think that Obama was not born in the United States.

And according to that same poll, 45 percent of Republicans cite Fox News as the television network that they turn to for news.

Incidentally, Fox News has fully embraced the latest incarnation of the birther conspiracy theory -- a theory that has long been discredited.

While it is impossible to infer from these polling results whether the Republican respondents who turn to Fox for news are the same Republican respondents who believe that Obama was not born in the United States, a December 2010 University of Maryland study sheds light on the connection between birthers and Fox. That study concluded that Fox News viewers were “significantly more likely” to adopt the false belief that Obama was not born in the United States.