Abstract
Research generally finds that while parties do influence roll call voting in state legislatures, this influence varies from session to session and from state to state. Potential explanations for this variation seem to be two-fold. First, it may be that factors varying from state to state, such as the nature of politics and political parties, may impact partisan influence on voting. Second, it may be that changes across time are responsible. For example, an influx of freshman legislators who are less knowledgeable about the legislative process may promote the ability of political parties to influence voting. Or, victories by a large bloc of candidates who are ideologically atypical of their party in a given legislature may affect that party's influence over voting. The key, then, to determining why party influence varies seems to rest with examining how the factors that influence votes vary.