Professor Kassow's research emphases cover topics within American politics, quantitative research methods, and comparative politics, with a particular focus on judicial politics and legal processes. His research focuses on why judges discussion of specific precedents (and types of usage of precedent) within court opinions, as well as focusing on how judges discuss various aspects of the law in court opinions. Professor Kassow has also worked on questions of how economic decisions by the U.S. Supreme Court impact economic inequality in the United States. Finally, Professor Kassow has research interests in theories of Congressional (and state court justice) representation. He has published in journals such as American Politics Research, Political Research Quarterly, and Justice System Journal.