I agree with Henry Farrell on this :
Bigotry derived from religious principles is still bigotry. Whether the people who implemented Bob Jones University’s notorious ban on inter-racial dating considered themselves to be actively biased against black people, or simply enforcing what they understood to be Biblical rules against miscegenation is an interesting theoretical question. You can perhaps make a good argument that bigotry-rooted-in-direct-bias is more obnoxious than bigotry-rooted-in-adherence-to-perceived-religious-and-social-mandates. Maybe the people enforcing the rules sincerely believed that they loved black people. It’s perfectly possible that some of their best friends were black. But it seems pretty hard to make a good case that the latter form of discrimination is not a form of bigotry. And if Friedersdorf wants to defend his sincerely-religiously-against-gay-marriage people as not being bigots, he has to defend the sincerely-religiously-against-racial-miscegenation people too.