WHEN BATTLES AND bruised feelings over controversial reviews and articles emerge, it’s useful to remember that what’s being graded is merely a strip of celluloid, rarely the private life and politics of a film director. Yet there was a time when directors themselves were graded politically, and if they received a ‘’restricted’’ rating they faced, quite possibly, the end of their careers in Hollywood.

The new David Fincher movie Mank focuses on writer Herman J. Mankiewicz, with his younger brother Joe popping in an out. The movie invents a principled stand for Herman — see my New York Times article this week and my award-winning book on the Upton Sinclair race, The Campaign of the Century — but it was Joe who actually took a brave position about sixteen years later. I first told part of this story in my book on the notorious 1950 Senate race between Richard M. Nixon and Helen Gahagan Douglas, Tricky Dick and the Pink Lady….

On Oct. 22, 1950, several hundred members of the Screen Directors Guild convened in emergency session in the Crystal Room of the Beverly Hills Hotel. One participant later called it ‘’the most tumultuous evening’’ in the history of Hollywood. The showdown over a loyalty oath that would deny any Communist affiliation had finally arrived.

On one side: The guild’s president, Joseph L. Mankiewicz, who faced ‘’the most dramatic evening in my life,’’ he later recalled. On the other: Cecil B. DeMille, one of the founders of the movie industry.

The Mankiewicz faction, led by John Huston, George Stevens and William Wyler, met before the meeting to strategize. ‘’Gentlemen, the fat is on the fire,’’ Huston announced. He had scribbled some notes on sheets of paper: ‘’hypocritical flag wavers . . . unappointed arbiters of loyalty . . . they have employed the very same tactics of those who they profess to have rallied against. . . .’’

It was the beginning of the season of the witch in Hollywood. Dalton Trumbo, Ring Lardner Jr. and other members of the Hollywood 10 had just been hustled off to jail, the penalty for refusing, in 1947, to answer questions about joining the Communist Party. A broad blacklist was still only a rumor, but after two years of relative quiet, another noisy, accusatory period was clearly approaching.