from a survey from the Program on International Policy Attitudes - with nearly 3000 people surveyed -

"To support the president and to accept that he took the US to war based on mistaken assumptions likely creates substantial cognitive dissonance, and leads Bush supporters to suppress awareness of unsettling information about prewar Iraq."

my favorite part - and the one that rings most true - esecially here is -

"The roots of the Bush supporters' resistance to information," according to Steven Kull, "very likely lie in the traumatic experience of 9/11 and equally in the near pitch-perfect leadership that President Bush showed in its immediate wake. This appears to have created a powerful bond between Bush and his supporters--and an idealized image of the President that makes it difficult for his supporters to imagine that he could have made incorrect judgments before the war, that world public opinion could be critical of his policies or that the President could hold foreign policy positions that are at odds with his supporters."

There are a bunch more statistics in the original article.  It can be found here - http://www.pipa.org/OnlineReports/Pres_Election_04/html/new_10_21_04.html

Dan