He has substantive research interests in political behavior, political geography, and American political development and methodological interests in spatial analysis, survival analysis, and time series analysis. His research agenda is motivated by the questions of whether and how American democracy functions effectively. He addresses these concerns by examining two sets of interactions between political actors that are central to these questions. The first focuses on horizontal interactions, employing a geographic lens to examine how the spatial interactions and spatial locations of actors shape their behavior. The second examines vertical interactions with a focus on the nexus of elite and mass behaviors. His research in political geography and elite-mass interactions focuses on three political behaviors: political participation, voting behavior, and opinion formation.