what do the black boys represent?

The "Black Boys" are Nurse Ratched's aids. They are dressed in white pants and act as Nurse Ratched's thugs. They do her bidding laying sadistic beatings on inmates. They do this to break any individual will an inmate might have. The only one they can't seem to break is McMurphy. They represent the the brutal tactics of the secret-police type men of a fascist dictator. They break the inmates both emotionally and physically so the Nurse can twist and manipulate them as she pleases.