I'm not going to read Marjorie Greene's entire statement so I might theoretically be missing some context, but what does she say here? "Communists aren't Americans and need to be locked up."
That's just McCarthyism. A bunch of nonsense we should have left behind.
Even if her accusations of communism were accurate, there isn't anything in the Constitution that says people who identify as Communists cannot be American citizens. On the other hand, birthright citizenship is specifically granted in the 14th Amendment.
I truly, honestly, believe that a congressperson saying that AOC, who was born in NYC, isn't American, is a violation of their oath of office. Marjorie Greene swore to defend the Constitution, and the Constitution couldn't be any clearer about AOC's citizenship. I also think that office holders who violate their oath of office should be removed from their office, and that it is the responsibility of other representatives to do so.