For most film buffs, On the Waterfront is not a politically controversial film — it’s simply one of the best films of all time.

Many know that the film’s director Elia Kazan did something shady, and some might even know that he testified against his former Communist allies at the House Un-American Activities Committee (HUAC). An even smaller group might know that after testifying, Kazan took out a full-page New York Times ad to justify his decision.

But for the American Left, Kazan is one of the worst traitors in American cultural history.