...same sex marriage threatens the Institution of Marriage,because it changes the definition of marriage. On the contrary, the objection I've been seeing here is that it extends traditional marriage to gays. A 'civil union', which many support as an alternative but which is available to heterosexual couples as well, redefines 'marriage' much more thouroughly - redefines it away, in fact.
"A civil union... is available to hertosexual couples as well,redefines marriage...redefines it away,in fact.
You made my point:same sex marriage destroys the institution of marriage.There is no reason why brothers and sisters or polygamists can't marry.