Homosexuality is based on a behavior. Race is not a behavior.
You bring up homosexuality as behavior. I believe that distinction is important. However, I differ from some of my close ideological allies. I would be opposed to sodomy laws in my state. I would be opposed to laws that criminalize private homosexual behavior or cohabitating.
That is different from my stance on marriage. Marriage is an institution that already has a history and purpose. Homosexual couples have no standing with regard to families and raising children.