Group size, turnout, and political alignments and the development of U.S. party coalitions, 1960-1992

We propose an approach for analysing trends in the contributions of social groups to electoral coalitions, and apply this approach to an analysis of the impact of changes in the race, religion, class, and gender cleavages on coalitions in U.S. Presidential elections between 1960 and 1992. We improve on existing studies of party coalitions by developing a multivariate model that measures group-specific political alignments while also correcting for changes in group size and turnout rates. Our analyses show that there have been significant changes in the contributions of different social groups to major party coalitions: the Democrats now receive more votes from professionals (and to a lesser extent, managers), blacks, and non-religious persons, and fewer votes from working-class voters; the Republican coalition has gained among managers (and to a lesser extent, professionals), while losing out significantly among liberal Protestants, blacks, and non-working voters. The analyses provide evidence of a slight convergence amidst a larger pattern of enduring group-based differences within the Democratic and Republican coalitions. The approach developed here can readily be extended to study electoral coalitions in other national contexts.