“McCarthyism” is often used to describe the period of intense repression of leftists in the US that occurred between the late 1940s and early 1960s.
One of the mechanisms of McCarthyist repression was the House Un-American Activities Committee (HUAC), which would force Communists to testify about their “activities”, including forcing them to name other Communists so the state could also persecute them.
Another mechanism was blacklisting. Courts ruled that workers could legally be discriminated at work against because they were communists1 and there was a bar on federal funding going to anything that employed communists, so they were sacked en masse from universities. There was also a “purge” of leftists from Hollywood.
Vigilante violence was also sky-high at this time, with a large number of left-wing civic institutions and people’s homes getting burnt to the ground, and left-wingers getting bashed publicly in the street.
Ultimately, McCarthyism was effective in destroying or neutering many institutions of the “Old Left”, from the CPUSA itself to the CIO, racial justice organisations, left-wing Jewish secular organisations, legal organisations for the defence of immigrants and workers, and so forth. What they could not do was suppress left-wing organisation entirely, and from the ashes of those institutions rose the New Left, which was heavily involved in the civil rights movement and the anti-Vietnam War movement, among other things.
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Indeed, modern US labour law pretty much allows all discrimination so long as a worker can’t prove it was because of their race, gender, older age, national origin, disability, the fact that they’d recently put in a complaint with the Labor Department, and in some states their sexual orientation or gender identity… ↩︎