Phrase used during the McCarthyite
? trials of the House Unamerican Activities Committee applied to both those who were believed--often falsely--to be engaged in political activities funded or otherwise supported by the Communist Party, and those who were believed to hold radical leftist political beliefs by those with radical rightist polical beliefs.
The phrase came from the title of the House Un-American Activities Committee formed in 1947 to investigate the supposed inclusion of Communist propaganda by Hollywood.
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