More than a Dime's Worth: Using State Party Platforms to Assess the Degree of American Party Polarization

How polarized are American political parties? Recently, Kidd used an automated content analysis program to demonstrate that American party platforms reveal only minor policy differences. In contrast to his conclusions, this analysis produces three main findings. First, at the state level, state party platforms reveal considerable ideological differences between the parties. Second, differences in state public opinion do not account for these differences; rather, they are more closely correlated with activist opinions and increases in state party competition. Finally, the conflict is not simply ideological but applies to specific issues in the platforms. As such, American state parties are highly polarized on different measures. Automated content analysis programs clearly represent an important methodological advance in coding political texts, but the results here call attention to the importance of policy and agenda content in party platforms. Moreover, studies of American politics, particularly research focusing on parties and ideological polarization, need to take into account the diversity of agendas that is inherent in a federal party system.