There would be a percentage of parents who would choose to abort rather than have a queer kid.
Once that started the queers would, in fear of the eventual eradication of their subset, demand that gay-gene uteri be protected in utero.
This protection can only be accomplished by acknowledging the legal right to the gay unborn to be born.
Knowing that this "right" could not be limited to gay uteri the feminist leg of the dem stool would fight like hell to deny it.
This would pit two of the most active and vocal camps within the dems against each other in a fight over abortion that would destroy the party.
Nuke the gay unborn whale.