They weren't voting for. They were voting against.
The unions were voting against "the bosses." Gays (most of them) were voting against straights. Other Democrats were voting against white men. Of course, neither GOP rank-and-file nor GOP candidates are necessarily white, straight, male, or "bosses"; but for very-low-information voters, neither stereotype nor voting-against is necessarily bad strategy.
However, these particular "enemies" don't actually harm other Americans, except psychically, by (1) being different, (2) dissenting (sometimes), and (3) being more successful (statistically). A free society allows these things, but many voters are, frankly, out of sympathy with such freedom.