Brendan Nyhan reads through the literature on false beliefs:
All survey responses are to a certain extent an artifact of the context in which they are solicited -- there is no way to measure what someone "really thinks." However, it's possible that people are expressing an ideological or partisan view as much as they are making a factual claim about the world. The strongest claim along these lines comes from Reason's Julian Sanchez, who suggests that misperceptions like the claim that Obama was not born in the U.S. are best conceptualized as "symbolic beliefs" rather than statements of what people believe to be literally true -- an argument that was subsequently endorsed by New York Times columnist Ross Douthat and ABC News polling consultant Gary Langer. Determining to what extent these beliefs are "symbolic" rather than literal is an important question for future research.
Funny how so many Christianists believe in the literal truth of oral mistranscribed centuries-old hearsay in the Bible, but not in a documented, proven historical fact in their own lifetimes. I suspect Ross's idea that this is all symbolism is a way to distance himself from the hateful nutters in his political coalition.