This essay traces the liberal to conservative changes in U.S. political attitudes and the effect these changes had on progressive and essentialist theories of education from the 1940s to the present. Focus is on the role Arthur Bestor played in these developments. Bestor was a leader of the anti-progressive movement during the 1950s and the most widely read educational reformer of that time. Initially the main difference between Bestor and his opponents was the relative place he gave to social problems and the liberal disciplines, but he grew increasingly conservative in his vision of educational reform, promoted essentialism in education, and called for a national commitment to liberal education. Bestor's educational background, ideologies, theories of curriculum, and opponents are discussed. Debates regarding teaching mainstream culture versus cultural pluralism, issues which divided Bestor and his progressive opponents during the 1950s, continue to divide liberal educators today. The document argues that because the Cold War is over and the political crisis that inflamed educational differences between progressives and essentialists is gone, it is time for progressive educators to acknowledge the value of Bestor's ideas and bring the educational Cold War to an end. Contains 153 references. (MM)