I think they see some kind of moral equivalence between a "married" homosexual and a serial adulterer/multiple divorced man. Actually, they probably imagine Pete is morally superior to Trump so "religious" people shouldn't have any problem voting for him. Now Trump is a repentant former adulterer who is faithful to his wife in a heterosexual marriage while Buttigieg remains an unrepentant homosexual and proud of it. His far left liberal policies are repugnant regardless.
And that’s what they will never understand.