On Oct. 2, USCIS issued policy guidance in the USCIS Policy Manual to address inadmissibility based on membership in or affiliation with the Communist Party or any other totalitarian party.
As of yesterday, members of communist parties may not emigrate to the US. Details are here text of the law is here
I know but the person I replied to seems to take issue with the notion of “excluding someone for wrongthink” in general, regardless of any side.