Partisanship and Ideology: A Subgroup Analysis Over Time Janet M. Box-Steffensmeier Suzanna De Boef Ohio State University Pennsylvania State University jboxstef@magnus.acs.ohio-state.edu sld8@psu.edu Prepared for presentation at the 1996 annual meeting of the American Political Science Association, San Francisco. Thank you to Jim Granato for helpful conversations and Jim Stimson for providing his dimensional algorithm. Thanks also to Erin Seper for her help with data collection and organization.