Of what use, then, are the American Communists?

They serve one function extremely useful to you and to the country, so useful that, if there were no Communists, we would almost be forced to create some. They are a reliable litmus paper for detecting real sources of danger to the Republic.

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

Also the vagus nerve.

Foul Coughing

The Pillage People

The Shite Stripes