Dropped randomly into this PPP poll (pdf) is the following line about Mississippi Republicans:
46% of these hardcore Republican voters believe interracial marriage should be illegal, while 40% think it should be legal.
If anyone tries to tell you there's not a racial component in the voting habits of white Republicans, they're being stupid or they're lying. No wonder Haley Barbour routinely blurts out racially charged dog whistle remarks from time to time. He's securing that 46 percent.