Due in part to a backlash against abuses perpetrated by the House Un-American Activities Committee, and in part to a landmark Supreme Court ruling in 1952 declaring films to be a form of free speech, Hollywood began to slowly liberalize. By 1962, the Production Code was virtually toothless. The newly formed Motion Picture Association of America implemented a rating system, which still stands today.
In 1969, following the release of Easy Rider, directed by liberal-turned-conservative Dennis Hopper, counter-culture films began to appear in significant numbers. By the mid-1970s, older directors were retiring, and a new generation of filmmakers was emerging. By the late 1970s, Hollywood was very openly and specifically liberal. After making his last film in 1965, Hollywood director John Ford saw the writing on the wall. “Hollywood now is run by Wall St. and Madison Ave., who demand ‘Sex and Violence,’” author Tag Gallagher quotes him as writing in his book, John Ford: The Man and His Films. “This is against my conscience and religion.”
Things are not much different today. In a 1992 letter to the New York Times, screenwriter and playwright Jonathan R. Reynolds laments that “… Hollywood today is as fascistic toward conservatives as the 1940's and 50's were toward liberals … And that goes for the movies and television shows produced.”
Conservative Hollywood -- How Conservative Hollywood Became a Liberal Town