Well, yeah. What's a vastly more widespread phenomenon, the homosexual lifestyle? Or, for example, guys wanting more than one lady sex partner....Predisposition!
The only non-"bigoted" position was that "married" should simply come to mean "US adult citizen." Single, gay, non-sexual arrangements, romantic, non-romantic, 1,2, 30 partners, etc., etc. Marriage became an institution for individual expression. Basically, what it is has been thrown open so wide, it actually isn't anything at all. It's like piercing your nose, now. Just, potentially, much more painful.
There is no longer a just argument for preventing consenting adults to form any and all "marriage" arrangements the human imagination can come up with. "Bigotry" was always a phony argument to allow a whole one other arrangement, discriminating against all others still left behind, without the justification of heterosexual coupling being naturally reproductive.