The whole class has read 1984, right? Memory of the book's a bit hazy, but ou could have at least one Goldstein figure who basically criticises the state, encouraging the class to join in; meanwhile, another person representing the state and Big Brother keeps track of who enters the debate most clearly and after some time periodically removes them from the room, representing the function Goldstein has in the book of providing some hope through which dissent is revealed and removed.