Partisan Effects of Voter Turnout in Presidential Elections

Previous studies of turnout effects in U.S. elections have reported perplexingly different results for presidential as opposed to major statewide (senatorial and gubernatorial) contests. By justifying and applying a consistent methodology, the authors find that results for both types conform to the pattern previously reported by Nagel and McNulty for senatorial and gubernatorial races. Outside the South, higher turnout helped Democratic presidential candidates from 1928 through 1964. In 1968 through 1996, however, the impact of turnout in straight two-party contests was insignificant, except in the South, where Democrats benefited from higher turnout. In the earlier period, high turnout helped Democrats most in states where Republicans usually prevailed. Its effects became weaker or even pro-Republican in the most strongly Democratic states. All of these findings uphold DeNardo's mathematical model, which provides an empirically supported theory of the partisan effects of turnout in U.S. presidential, senatorial, and gubernatorial elections.