"President Obama has had a hard time dislodging misperceptions about his health care proposal — those stubborn beliefs that there are death panels and free care for illegal aliens that don't actually exist in the legislation. Recent research about the way people defend their faith in false information, though, suggests calling out the inaccuracies may not be all that effective in converting the suspicious.
Sociologists at the University of North Carolina and Northwestern University examined an earlier case of deep commitment to the inaccurate: the belief, among many conservatives who voted for George W. Bush in 2004, that Saddam Hussein was at least partly responsible for the attacks on 9/11.
Of 49 people included in the study who believed in such a connection, only one shed the certainty when presented with prevailing evidence that it wasn't true.
The rest came up with an array of justifications for ignoring, discounting or simply disagreeing with contrary evidence — even when it came from President Bush himself."