what happens to mr taber under nurse ratched's care? why do you think the author includes this information about mr taber at this point in the story

One of the patients on the ward, Mr. Taber complains to Nurse Ratched that he does not know what is in his medicine. Nurse Ratched claims that he was once a manipulator, like McMurphy, and she eventually made him submit through her tyrannical punishments. The Mr. Taber character foreshadows McMurphy's eventual fate.