Book excerpt: This is the first book-length study of the triumph of the Reuther caucus over the Thomas-Addes-Leonard coalition in the United Auto Workers union. The dramatic defeat of the left-center coalition had far reaching significance. It helped to determine the shape of postwar labor relations, the direction of postwar liberalism, and the fate of the left. Based on manuscript sources, oral histories, and quantitative analyses of convention roll calls, UAW Politics in the Cold War Era places this union conflict in a national political context of postwar economic conflicts, the cold war, and the passage of the Taft-Hartley Act. Halpern offers a fresh point of view on the character of the two contending coalitions and the reasons for the Reuther triumph. His work is a valuable contribution to the current reassessment of the domestic politics of the early cold war years.