If there wasn't a pro-Obama Dungeons and Dragons Crowd before the comment, there certainly was after. Wizards of the Coast sent a response to the McCain campaign, pointing out the remarks were disparaging, the number of military personnel who play, and Hasbro's donation of crates of product to support GIs across the globe. A Facebook group, named the Pro-Obama Dungeons and Dragons Crowd started and had several hundred followers (archived here) I was one of the administrators of said group.
McCain may have lost his opposed Charisma check with Obama, but the presidential D&D references continue in the 2012 campaign. Mitt Romney is shown courting votes at an RPGA convention on Saturday Night Live:
Go to 3:03 if you don't want to see the whole thing. We've also have some character sheets for numerous candidates here and here. Enjoy!