Inter-Party Constituency Differences and Congressional Voting Behavior

Academic studies of roll-call voting in Congress have tended to stress two factors: (1) the substantial degree of party cohesion in Congress on most issues, and (2) the importance of constituency factors in explaining deviations from party votes within parties. These studies indicate that party is the single most important predictor of roll-call behavior, and that constituency factors explain most of the deviation from party votes. No such study, however, describes constituency differences between Democrats and Republicans on the national level—that is, inter-party differences on constituency variables as opposed to intra-party differences. We will attempt, in this study, to demonstrate that differences between Democrats and Republicans are not merely a matter of party label or ideology (few really contend otherwise), but that they are rooted in basic differences in the kinds of constituencies from which Democrats and Republicans come. We will then go on to show that these constituency factors are also important in explaining intra-party differences in voting in Congress, but only by way of supporting the hypothesis that party voting patterns reflect constituency differences. The general theory underlying this analysis posits gross relationships between sociological variables and political behavior, especially in democratic systems which permit relatively wide latitude in political activity. Since shared attitudes about various problems confronting people are often the result of sharing similar environments, and since economic and social environments vary widely in the United States, it is not surprising to find people located in similar environments choosing up sides in similar ways on matters of public policy, and differing with those who do not share the same environment. These effects should be most noticeable in relatively small areas, such as congressional districts.