After WWII the United States faced off against a new adversary, its former ally the Soviet Union. No shots were fired, but the two superpowers existed in a constant state of alert. In America, the fear of Soviet takeover amounted to a kind of national pathology. Demagogues like Senator Joseph McCarthy had their day, exploiting the fear of communism for political gain.
In Hollywood, the requirement of a loyalty oath was supported by some, and names were named in Congressional testimony. As one critic said of the Hollywood informers, “they lied, not to save their lives, but to save their swimming pools."
It was during this period that over 300 members Screen Directors Guild (subsequently known as the Directors Guild of America) met on October 22, 1950 to discuss a new proposal which would require all directors to take an oath of loyalty to the United States and file detailed reports about the loyalty of all their co-workers. The Hollywood establishment was worried that accusations of communist leanings would bring sanctions from Washington and a vocal segment of the industry vowed to clean house.
I'll let the DGA's official historian take it from here.
It's a thrilling procedural, with Cecil B. DeMille as the instigator of the loyalty proposal and cast of characters including Frank Capra, John Huston, Nicholas Ray, Robert Wise, Vincente Minnelli, Fritz Lang, Joseph L. Mankiewicz, George Stevens, and, maybe most iconically, John Ford, who delivered the coup de grâce to DeMille's witch hunt:
"Finally, after midnight, Ford raised his hand with a director's sense of drama and timing.
"My name is John Ford. I am a director of Westerns…. I have been sick and tired and ashamed of this whole goddamn thing—I don't care which side it is," Ford told the crowd. "If they intend to break up the Guild, they've pretty well done it tonight…. I don't think we should [be] putting out derogatory information about a director, whether he is a Communist, beats his mother-in-law, or beats dogs. That is not our purpose."
Playing the conciliator, he added, "I don't agree with C.B. DeMille. I admire him. I don't like him, but I admire him....You know when you get the two blackest Republicans I know, Joseph Mankiewicz and C.B. DeMille, and they start a fight over communism, it is getting laughable to me."
The Guild, Ford said, was in crisis and needed to clean house. Then he dropped his bombshell: "There is only one alternative, and that is for the board of directors to resign and elect a new board." His words were greeted with a roar of applause and cheers.
Ford's proposal offered a way out, and the bleary-eyed members, some of whom were due on their sets in only a few hours, voted on the motion by ballot. The announcement by Mankiewicz of its passage earned the night's final ovation, whereupon each of the board members rose to offer his resignation. The image of a battered, humiliated DeMille descending from the podium and withdrawing defiantly to the back of the hall was a memory few would forget."