Is that implying that Evangelicals are essentially racists? Jim Crow stopped about the time that the Sexual Revolution got going strong, so there's some confounding factors there. Since the Sexual Revolution values are clearly against the Christian "rules", which at the time somewhat matched the legal rules, and there was a secular movement removing the legal rules, it would seem likely that this was the motivating factor, especially given the existence of groups named like "Moral Majority" (ick). Also, Evangelicals are not just a southern thing, and I've never heard Evangelicals (I've not been to the South) argue for any return to anything remotely near Jim Crow, but I've heard lots of talk deploring sexual mores.