Super Medians

Published in 2008. In the Stanford Law Review 61:37-100

Lee Epstein
Tonja Jacobi

It is not surprising that virtually all analyses of the Supreme Court stress the crucial role played by the swing, pivotal, or median justice: in theory, the median should be quite powerful. In practice, however, some are far stronger than others. Just as there are "super precedents" and "super statutes"—those that are weightier or more entrenched than others—there are "super medians"—Justices so powerful that they are able to exercise significant control over the outcome and content of the Court's decisions.

Conventional wisdom holds that Justices accumulate power by virtue of their personality, methodological approach, or even background characteristics. But our analysis suggests the opposite. Using sophisticated theoretical tools and systematically developed data, we demonstrate that the strength of the median has less to do with who occupies the center seat than with those Justices who sit close to the center. When median Justices are ideologically remote from their nearest colleagues, they will emerge as super medians. They will find themselves on the winning side of cases, breaking ties throughout the term, and authoring opinions in key cases. But when medians are ideologically proximate to their closest colleagues, they will be far less dominant.

This analysis has important implications for historical understandings of the Court, for identifying the best strategies for attorneys arguing before the Justices, and for predicting whether new appointees will affect the direction of the Court's decisions. We provide advice for advocates, as well as Presidents and Senators contemplating judicial appointments, and identify plausible nominees for future Republican and Democratic administrations.

Click here for the article (.pdf)
Click here for the data (Stata .dta file) (posted on March 3, 2008)