There's some different race related history stuff in the US, but this sort of thing doesn't just happen in your church. Typically, Southern churches don't really like queer people, doesn't matter if they're black churches or white churches. White churchgoing Christians also have an added element of racism. Because the white Christians also tend to be racist, they're more likely to like Reagan and the Republican party that's existed since then. Black people tended to vote for the Republican party for decades after the Civil War because it was the party that Abraham Lincoln was part of. Partially due to the New Deal's programs, many black people switched to the Democratic party and stuck with it, likely due to social programs that help many members of the community, such as food stamps. There's plenty of other examples of people within the Democratic party that don't like certain parts of its platform, such as many Catholics and abortion rights. It's also pretty easy to find queer people that are racist as fuck. People being part of one minority group has less bearing on their biases as one might hope. Hopefully none of this is horribly wrong.