Fisty, went looking... Found a few references, but nothing concrete... Check wiki, for instance, but I don't consider wiki a good source.
I _do_ remember my childhood in the south. And a sudden swing when the religious folks were suddenly Republicans - Falwell's Moral Majority, etc...
FWIW, we had some of Jim and Tammy Faye's folks move into town (and those folks were -tacky-), and we tended to pay attention to that sort of thing...