This reminds me of a conversation I had with my father, the year after I started college. In response to hearing about gay marriage, my father said it would set a bad precedent because then "everyone would think it's okay to be gay/Black/White/whatever", to which I responded, "Dad, people are BORN gay/Black/White/whatever".

"But homosexuality is condemned in the Bible, and we should follow the Bible," he said, because everything would be better if we followed God's word to the letter.

I reminded him that if he really wanted to go that route, the Bible also advocates genocide and stoning of adulterers. Point being, it's a brutal bit of writing and has no place as a code of law in a just government.