Now hold on. I cannot BELIEVE I am actually saying anything even tangentially in defense of anti-gay people, BUT...
It's a little unfair to say "gay marriage opponents" say this. One person did. A senator's wife, sure, but even if that one senator thinks that way, or he's swayed by his wife, it doesn't change much. That's one vote out of 100, and to ascribe the racist sentiment to ALL gay marriage opponents is unfair.
Instead, feel free to use any of the OTHER stupid shit other gay marriage opponents say to nail them to a wall.