The talented screenwriter Dalton Trumbo (1905 – 1976), known primarily for being the mascot of the Hollywood Blacklisted screenwriters, did not do himself any favors when he wrote the attached essay outlining his sympathies for Stalin's Soviet Union at the expense of the United States. A year later he would find himself in the hot-seat in front of the House Un-American Activities Committee (1938 - 1975) where his non-cooperation landed him eleven months in the hoosegow on contempt of Congress charges.
More articles about the Hollywood Blacklist can be read here...
With the passing decades, Hollywood executives have discovered that they can blacklist conservatives and no one seems to care as much. This subject was addressed by Ben Shapiro in his 2012 book (from Amazon):
Primetime Propaganda: The True Hollywood Story of How the Left Took Over Your TV
- the 2014 movie from Amazon: