This is one of the problems I see in this issue generally. One side has decided that a key aspect of the debate is settled and beyond further discussion: Opposition to same-sex marriage is the same as opposition to interracial marriage. If one side accepts that as a truth, set in stone, then talking these matters over reasonably and rationally is pretty hard.
Ryan Anderson is one of several scholars who have discussed the issue of whether opposition to interracial marriage is the same as opposition to same-sex marriage.
Here's an article he wrote on the subject. I think you'll see he's a rational guy:
Anyway, agree of disagree, but don't tell me the debate is over.