What is the real structure of substantive conflict in American politics during the postwar years? Is it even possible to talk about an ‘issue structure’, about ongoing policy conflict within continuing policy alignments, at the mass and not just the elite level? If so, what is the structure of substantive conflict characterizing the mass politics of our time? How do policy issues cluster, and nest, in the practical environment for mass politics? And how does such an issue structure relate to (and shape) electoral conflict? Has this relationship remained essentially constant over the last half-century, the period when public opinion data are most widely available, or are there major break-points, and when did these occur? The search for a continuing structure characterizing public preferences on policy conflicts across the postwar period is the principal challenge of this paper. To that end, consistent measures of public preference in four major issue domains–welfare policy, foreign policy, race policy, and social policy–are sought, developed, and analyzed. A theoretical grounding is derived from the literature on postwar political history. An exploratory analysis applies this theoretical grounding to the American National Elections Studies, 1948-2000. A confirmatory analysis is applied to these exploratory findings, as informed by the literature on public opinion in specific issue domains, which provides a further set of independently testable propositions. And the result is an ongoing issue structure. The application of this structure to voting behavior in presidential elections is then the main secondary task of the paper, yielding what is in effect a pure politics of public policy. In this, social welfare proves to have been the leading policy concern of American voters across the postwar period. But international relations was normally present and often important, while civil rights and cultural values made occasional but still noteworthy contributions. From one side, social welfare also had the most consistent impact. From the other, it was nevertheless international relations that divided the postwar years into coherent periods. By contrast, the domain of civil rights and the domain of cultural values, along with one of the two key aspects of foreign policy–foreign engagement, the continuum from isolationism to internationalism–all changed the actual direction of their partisan impact from the immediate postwar period to the modern era. [ABSTRACT FROM AUTHOR]