Same-sex marriage and interracial marriage are apples and oranges. Interracial marriage didn't redefine the genders of the people involved in a marriage. It is still man-woman marriage.
SSM turns Western Civilization on its head. Is there anyone who doesn't know that in the states where SSM is legal the next iteration of these supposed "civil rights" will be legality for polygamy? If SSM is legal, there are no legal impediments to polygamy. We are headed down the road to barbarism.