Communism is so repugnant to almost all Americans, when they are getting along even tolerably well, that one may predict with certainty that any social field or group in which the Communists make real strides in gaining members or acceptance of their doctrines, any such spot is in such bad shape from real and not imaginary social ills that the rest of us should take emergency, drastic action to investigate and correct the trouble.

Unfortunately we are more prone to ignore the sick spot thus disclosed and content ourselves with calling out more cops.

--Robert A. Heinlein, Take Back Your Government

Heinlein fucking hated communists (leaving aside for the moment the meaningful distinctions between socialism and communism), and even he was smart enough to acknowledge that if the group you don't like is gaining converts, then you've done something wrong to let them seem appealing.