How does this rhetorical device contribute to his message and essay's power?

"that year in new jersey lives in my mind as though it were the year during which, having an unsuspected predilection for it, i first contracted some dread, chronic disease, the unfailing symptom of which is a kind of blind fever, a pounding in the skull and fire in the bowels. once this disease is contracted, one can never be really carefree again, for the fever, without an instant's warning, can recur at any moment. it can wreck more important things than race relations. there is no negro alive who does not have this rage in his blood - one has the choice, merely, of living with it consciously or surrendering to it. as for me, this fever has recurred in me, and does, and will until the day i die" (notes of a native son)