To say that I am not homosexual but I believe homosexuals should be treated equal, is like saying:
I do not mix with other races but I believe racism should be stopped.
Since homosexual is not an identity but a practical characteristic such as temper, talkativeness, etc., it cannot be equated with identity of races such as whites, blacks, Asians, etc.
Using racism to support gay marriage
An easy defeat.
Racism is in the broad sense, preferring one's own race over the other.
Homosexuality is preferring one's own gender over the other.
So, it is ironic, that gay advocates would use racism, the very tool for their own defeat, to support their claim.
"But homosexuality is an orientation, not preference!!!"
Simple, then just look at racism as an orientation.