Is communism illegal in the U.S. because of the Communist Control Act of 1954?

Question

The Communist Control Act of 1954 was designed to protect America from communism. Among other things - it made membership in the communist party illegal. An Arizona judge ruled it was unconstitutional in 1973 (but the supreme court didn't).

Does this mean people could be arrested assuming they are in the right juristdiction for

1. Joining the communist party in an American college years after the fact?

2. Immigrating from a communist country where party membership is either very encouraged or mandatory?

EDIT

It would almost certainly be declared unconstitutional eventually. Would this be at the hearing after the arrest? What prevents someone from using this to harass people, and arrest a new group every few months?

For example - a college student is arrested for joining the communist party and taken to jail. What would the process be to drop the charges? Does anything happen to the arresting officer?

Answer 1

A person cannot be arrested unless they are suspected of having committed a criminal offense. The Communist Control Act does not create a criminal offense of being a communist, instead §843 states that a communist

shall be subject to all the provisions and penalties of the Internal Security Act of 1950, as amended [50 U.S.C. 781 et seq.], as a member of a “Communist-action” organization.

But those provisions concerning communist-action were repealed in 1993¹. Therefore, a prosecution would go nowhere.

^{1 - The statute requiring communists to register was already repealed in 1968}