Communism is a handy boogeyman because americans are already heavily conditioned to accept it due to red scare propaganda and it also can be used to invalidate anything vaguely lefty like minimum wage laws, labor standards, unions etc as extremist instead of completely fucking normal centrist things that aren't even slightly controversial in the rest of the world. Got to keep those profits up and wages low after all. Hard to do if you actually have to engage with serious efforts to make things better rather than tribal shitflinging.