Starting in the 1950s, the Russians sent agents into our universities, media, and entertainment sectors to plant and nurture communist ideology. So, although American communists promote it, they received plenty of training directly from Soviet operatives.
Today’s American communists are split into two camps. The smart ones know that Americans will never accept limits on freedoms if they try to take away our rights all at once, so they get elected to office to implement Communist goals gradually or work in media/entertainment to indoctrinate people with Communist ideology in the form of news or entertainment. The dumb ones want dictatorship now and stage riots to try to force it.
Either way, ordinary American citizens lose.
Starting in the 1950s? Long before that. The Communist Party USA, officially the Communist Party of the United States of America, is a far-left communist party in the United States established in 1919 founded by C.E. Ruthenberrg after a split in the Socialist Party of America following the Russian Revolution.
A good timeline is here:
https://depts.washington.edu/moves/CP_intro.shtml
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