Someone better tell these people they all could be arrested at any moment!
https://en.m.wikipedia.org/wiki/Communist_Party_USA
No but seriously it’s an unenforceable junk law that no one has bothered to take the time to repeal that was never even really used in the first place. I mean, the communist party runs candidates for office to this day. Someone finally tried to use it in 1972 to keep a communist candidate off the ballot and a federal district Court promptly ruled it unconstitutional.
https://www.plainsite.org/dockets/1zey0ee5l/arizona-district-court/blawis-v-bolin/
I’d say more broadly the legal and political system works against any organizations that threaten the status quo, but yes America’s attitudes toward communism have been pretty obvious throughout the twentieth century. I just took issue with the idea that political parties or idealogies are illegal in and of themselves in the US, constitution still manages to protects some things.