One of the most important career decisions for a legislator is the decision to switch parties, and it raises a theoretical puzzle: it carries significant risk, yet sometimes legislators do change partisan affiliation. We elucidate this puzzle with the first-ever systematic comparison of the entire careers of state legislative switchers and non-switchers in the American South, where the high prevalence of party switching coincided with rapid realignment toward the Republican Party. Our analysis is the first to evaluate all post-switch career decisions (retiring, running for reelection, running for higher office) simultaneously, and it is the broadest in its scope with two full decades of career data. We demonstrate that converts to the Grand Old Party (GOP) pay a reelection cost. However, they are less likely to retire than Democratic non-switchers and more likely to seek higher office. This latter finding is especially strong during the earlier part of our study—when the Republican bench in the South was not as deep and competition for the party label was not as intense. Our findings suggest that political ambition motivates legislators to trade short-term electoral costs for a more promising long-term electoral career with the ascendant party.
