However, here's what confuses me: almost every single one of the anti-Trump members—outside of me and maybe two other people—was extremely homophobic and transphobic. They were also all strongly pro-life. They hated abortion and viewed it as "murder." One kid in the church literally said, "Gay people deserve to be hurt."

I mean, for starters have you tried asking? As for my guess, probably because they have other political positions that push them towards democrats. Sticking to social issues, "fuck racism and the gays" is a coherent position one can take, and if they hate racism more than they hate people then they'll lean democrat. And then you have economic issues; supporting better social welfare, environmental regulation or public transport automatically will essentially lock them with the DNC. There are more variables affecting someone's political affiliation than how they feel about gay people.