Richard Polenberg, One Nation Divisible: Class, Race, and Ethnicity in the United States Since 1938 (New York: Viking Press, and Harmondsworth: Penguin Books, Ltd., 1980, £1·95). Pp. vii, 363. Alec Barbrook and Christine Bolt, Power and Protest in American Life (Oxford: Martin Robertson, 1980, £15·00). Pp. ix, 375.