Abstract
Legislators will sometimes vote against their party’s position on roll-call votes to differentiate themselves from the party mainstream and to accrue a “personal vote.” Research suggests that the use of rebellion to generate a personal vote is more common (1) among majority party members and (2) among ideological extremists. But these majority party extremists only have a strong incentive to rebel in situations where the accrual of a personal vote is electorally useful. In this manuscript, we evaluate variation in rebellion rates of state legislators in the United States conditional on ideological extremism and majority control. Using donation-based measures of ideology and roll call–based measures of party loyalty over a twenty-year period across more than 30,000 legislators, we find that when legislators have little incentive to differentiate themselves from their parties, this “strategic” party disloyalty among majority party ideological extremists is limited. However, when legislators have strong incentives to craft a personal vote, ideological extremists defect from their party more often than their moderate counterparts. In particular, we find greater evidence for this type of strategic party disloyalty in states with high intra-party competition and low inter-party competition and less evidence in states with high inter-party competition.