Contestation versus Replacement: Republican Party Gains in Southern State Legislative Elections

Abstract

This study tests two theories of how support for Republican candidates has increased in Southern state legislative elections between 1968 and 1988. The first, called the rising tide hypothesis, asks how much of the Republican gains were due to a growing number of Southern Republican voters and, therefore, to growing support for Republican candidates over Democratic incumbents in general elections. The second, the replacement hypothesis, theorizes that incumbent Democrats receive consistently minor competition during their careers, yet Republican open seat candidates do increasingly well after Democratic incumbents retire. The data consists of an ICPSR dataset of state legislative elections from 1968 to 1988 in Alabama, Mississippi, South Carolina, and Texas. The results show that while both dynamics are at work, the replacement effect is over three times larger than the rising tide effect.