The slippery slope argument against SAME SEX MARRIAGE is valid but inconsequential and no reason to deny rights. You seem to disagree?
What the heck is real issue? Why don't SSM advocates embrace polygamy, or at least acknowledge that legal ssm will open the door to plural marriage? Are they so afraid of the backlash of public opinion, that they don't have the courage to admit this? This whole notion of "marriage equality" contains within it the acceptance and recognition of plural marriage relationships.