The Success of Amici in State Supreme Courts

Abstract

During the past decade, interest group participation in state supreme courts has continued to increase, reflecting the increasing importance of these courts as policymakers in the federal system. Groups participate both as sponsors of litigation and as amici curiae, but little is known about either role. The present analysis explores the success of amici curiae in state supreme court decisions on the merits. Three methods of assessing the relationship between amici support and litigant success are employed: their simple won/loss ratios, their success in "matched pairs," and the relationship between amicus sup port and the success of litigants in state courts in a multivariate logit model. All three methods suggest that support from amici is significantly related to the likelihood of success of the supported litigants, regardless of whether amici support the appellant or the respondent.