"There is a fundamental similarity between the persecution of individuals who engage in consenting homosexual activity in private, or who ingest, inject, or smoke various substances that alter their feelings and thoughts—and the traditional persecution of men for their religion. … What all of these persecutions have in common is that the victims are harassed by the majority not because they engage in overtly aggressive or destructive acts, … but because their conduct or appearance offends a group intolerant to and threatened by human differences."