This is an adaptation of the group game "Mafia".
Students are given context for McCarthyism (the Red Scare) and are assigned roles to play in the game. I assign roles by using a deck of playing cards, and handing out the cards to the students once they are seated. It is best to reiterate to them that their identity is a secret!
Teacher acts as the moderator, and accusations fly as students accuse each other of being communists, rather than "killing" a character, like the traditional Mafia game, a student who is accused and found guilty of being a communist is blacklisted.
My students LOVE this game, it's a game most kids are at least somewhat familiar with, and once they get the hang of it, it goes very smooth. It's a great way for them to understand how easy it is to accuse others when facing accusation yourself!