While I wouldn't have excluded Communists, past Communists, or Communist sympathizers from all federal jobs (not because I like them, but because of the First Amendment), I surely think it's perfectly constitutional and proper to exclude them from secret nuclear weapons research.Huh? Change "Communist" to "Nazi," or "al Qadea," and Volokh comes off looking like a fool--the wrongness of his view is plain. Heck, just change it to "Klansmen" and he doesn’t look any better.
The Communist Party stood for the violent overthrow of America and the forcible installation of a communist dictatorship. People are free to hold whatever ideas they choose, but they can not act on ideas that call for the initiation of force. Membership in the Communist Party was just such an act; it was membership in an organization that had it succeeded in its goals, would have resulted in the destruction of the principle of individual rights and the American way of life.
The failure to condemn the communists is the failure to condemn a movement that brutalized and murdered millions. People are outraged over the absurdity of the holocaust deniers, but what about the absurdity of those who mitigate communist atrocities--people who seem to forget just what the communists stood for and the cost of their handiwork?
The question of the communists in America in not a question of the First Amendment. It is a question of whether a nation is obligated to either protect or prosecute those who seek its destruction.