Having reached the end of our investigations, we can now consider in greater detail the political and theoretical relevance of our results. Understanding the social bases of the two major political parties in the United States cannot, by itself, explain which party is likely to win the next election. There are many other causal factors than social cleavages that affect election outcomes. Moreover, a central assumption of our approach is that the political consequences of social cleavages for electoral outcomes are mediated by other, more proximate factors (which in turn have multiple causes). None the less our findings have implications for the future trajectories of the Democratic and Republican parties in light of postindustrial social and economic developments and cultural changes in American society. We identify the most important of these changes and their likely impacts on the social bases of party coalitions below.
In terms of theoretical issues, our work suggests some ways of thinking about the utility, as well as the limits, of what we have called the 'sociological approach' to studying political behavior. A growing chorus of scholars have argued that social cleavages have declined in political importance throughout the mature democracies. Although based on limited empirical evidence, this conclusion has been widely accepted and interpreted as both an indicator and cause of contemporary patterns of political change. We find little evidence for this sweeping conclusion in the U.S. context. The total social cleavage--the average of the race, religion, class, and gender cleavages--has actually increased in size during the twelve elections between 1952 and 1996. While a significant portion of this increase is attributable to the growth and durability of the race cleavage, our conclusions about the overall stability of the total social cleavage would not be affected by ignoring the racial cleavage.
In this chapter, we examine in more detail these political and theoretical conclusions. We begin with a discussion of the political consequences of changing social group alignments for the Democratic