There is a "God Gap"...for whites and Mex-Ams, anyway: Razib links to a survey which reports that the "God Gap" between Democrats and Republicans is not as large as is conventionally thought. The survey fails to discuss differences by race, so let's help them out. I'll cut to the chase and only look at how often people go to church, and how they vote. If they attend religious services at least once a month, I categorized them as religious. The General Social Survey does not have voting behavior more recent than the 2000 presidential race.
Church attendence differentiates white voters (especially Nader fans from the rest) and it differentiates Mex-Ams even more. On the other hand, African American Gore voters are just as religious and three blacks who voted for Bush. When I addressed previously the question about what does differentiate black GOP from Democrat voters, the only thing I found was that men are more often Republicans. (I don't present Nader numbers for the two minority groups since sample sizes are too small).
While there are differences here, people like Ann Coulter who say that Democrats are godless exaggerate wildly, even if speaking of whites: two-fifths of whites, one-half of Mexicans, and three-quarters of blacks who voted in 2000 for Gore go to church at least once a month.