I need help finding literary criticisms that help prove my thesis that power and the struggle for power can be deadly.
It seems to me that your thesis is too broad. Try and be more specific. Who in the novel are you concentrating on? MCMurphy? Nurse Ratched? The Chief? The other inmates? Some literary critics and "schools" that have used power in their writings include Michel Foucault, Marxism (Fredric Jameson), Feminism, Psychoanalysis, Culturalism, Multiculturalism, etc. You see, most literary theories speak and analyze power and power mechanics, we just need to know the power relations between whom. Between Ratched and McMurphy? Feminism. Between McMurphy and himself? Psychoanalysis. Between the inmates and the rest of the world? Cultural criticism. Between McMurphy and the rest of the ward / world? Mythical criticism. Everything is perspective.