One big party? An assessment of state and national intra -party ideological unity

Scholars have long criticized the American political party system as decentralized, fragmented, and pragmatic in nature, with little ideological space between the two parties and a lack of ideological cohesion within. By 1950 the American Political Science Association issued recommendations for stronger, more ideologically cohesive parties to overcome these weaknesses. Some studies in recent decades suggest there has been a shift to a more nationalized political environment. In this dissertation I seek to assess the extent to which intra-party ideology is nationalized, consistent with the goals of the APSA report. I examine the content of all state party platforms in effect in 2007 and compare them to their national committee's 2004 platform to assess ideological unity. I then test models to determine influences on ideological unity within the Democrat and Republican parties.;I find state Democratic parties display a wide range of policy preferences, yet as a whole are ideologically compatible with the policies advocated by the Democratic National Committee. On the other hand, state Republican parties are more homogenous in their policy preferences, reflecting a cohesive ideology; yet, these state parties are ideologically fragmented from those preferences expressed by the Republican National Committee. Factors affecting intra-party unity differ by party. Democratic unity is influenced by organizational and institutional factors. Republican unity is slightly affected by regional characteristics.;While each party is unique in terms of intra-party unity, state parties of both parties continue to craft policy messages that are suited to their local political environment. Despite the remaining independence of state parties to differ with their national committee, the Democrats' ideological compatibility and Republicans' lateral homogeneity demonstrate that both parties have at least moved closer to ideological coherence as advocated by the APSA nearly sixty years ago.