It should be noted that "communism naturally appeals to the downtrodden" wasn't historically true. Communism, in practice, advocated a super-powerful state, and the workers all knew (from experience) that the state was the instrument of the rich. Regularly, state power was used to crush strikes with a lot of violence.
The notion of a state-glorifying ideology as a solution (correctly!) seemed like fucking lunacy to most workers around the turn of the century. It took communism a lot of effort to find the right talking points to convince workers to join "the cause"; and in the USA, this arguably never worked. Which they only managed to find a way around later on: subverting the intelligentsia, instead of the workers. (They knew this worked, because in Europe, the intelligentsia were the carriers of communism in the first place.)
I re-state: communism does NOT appeal to the workers, or at least not naturally. Communism actively and consciously DECEIVES the workers. Communism actually appeals to a lot of academics and to central planners and other bureaucrats... because it gives them all the power in society.
