Collegial Influence and Judicial Voting Change: The Effect of Membership Change on U.S. Supreme Court Justices


  • This article reflects the views of the authors and does not necessarily reflect the views of the Congressional Research Service or the Library of Congress. For helpful comments and conversations on this work, we thank Lawrence Baum, Lauren Bell, Eileen Braman, Corey Ditslear, Rich Pacelle, Jeff Staton, and Margaret Williams, and we thank Carl Marchioli for excellent research assistance. Portions of this research were presented at the 2005 American Political Science Association annual meeting. Authors are listed alphabetically.

Please direct correspondence to Scott Meinke, Department of Political Science, Bucknell University, Lewisburg, PA 17837; e-mail:


Understanding the source of voting changes by appellate judges provides an important window into the factors that shape the votes of the judges more generally. We argue that membership changes, by altering the collegial context in which judges make their choices, affect the information environment, long-term collegial considerations, and short-term strategic calculations. As a result, membership change should lead to greater uncertainty and more frequent voting changes among continuing justices in the term following a replacement. We test this proposition by looking at vote change by justices of the U.S. Supreme Court in two separate analyses: justices' votes on search-and-seizure cases since Mapp v. Ohio (1961) and on the progeny of Miranda v. Arizona (1966). Our results support the argument that the collegial context helps explain changes in voting choices. Our analysis suggests that collegial considerations are an important component of judges' behavior and merit further evaluation in a cross-national context.