The radical is so often imagined as the marginal that sometimes the truly subversive escapes detection just by showing up in a tuxedo instead of a T-shirt or a ski mask. Take Giant, the 1956 film directed by George Stevens. It stars Elizabeth Taylor and features three queer men, Rock Hudson, James Dean, and Sal Mineo, who uneasily orbit one another in ways that seem only partly about their cinematic roles.

This is what caught my eye the first time I saw Giant. It was the thirtieth-anniversary screening at San Francisco’s Castro Theatre, the great 1,400-seat dream palace where,…