Liberal pastor preaches fundamentalism, in a round about way...

The question is a straight forward one. Why is it accepted to defend one's bigotry against gays by referencing one's religion, while it is no longer accepted as a way to defend slavery or opposition to women's suffrage?

Really, he's arguing against cherry picking. He's arguing that you should take all of the Bible or none of the Bible. That if you no longer defend one type of bigotry with the Bible you should no longer be permitted to defend any type of bigotry with it. Well, I have to admit, that's a pretty good point. Lets either bring back slavery or give everybody equal rights regardless who they love.