No surprise here. According to a study by the Program on International Policy Attitudes at the University of Maryland, Bush supporters aren't part of the reality-based community.

Analyzing data from a series of nationwide polls, the report finds that a majority of Bush supporters believe things about the world that are objectively untrue, while the majority of Kerry supporters dwell in the reality-based community. For example, Bush backers largely think that the president and his policies are popular internationally. Seventy-five percent believe that Iraq was providing "substantial" aid to al-Qaida, and 63 percent say clear evidence of this has been found. That, of course, would be news even to Donald Rumsfeld, who earlier this month told the Council on Foreign Relations, "To my knowledge, I have not seen any strong, hard evidence that links the two."
Though its language is dispassionate, the report lays responsibility for this epidemic of ignorance at the White House's door. "So why are Bush supporters clinging so tightly to these beliefs in the face of repeated disconfirmations?" it asks. "Apparently one key reason is that they continue to hear the Bush administration confirming these beliefs."

Not too surprising given the earlier PIPA study showing that watching Faux News makes you stupid. Or, perhaps it's just that stupid people watch Faux News. Probably a feedback loop occurring somewhere here.
I'm not going to say that being a Bush supporter makes you stupid, or that you have to be stupid to support Bush. But, the evidence is compelling.