There is a rich history of scholarship demonstrating that interest groups have influenced judicial policymaking, but there has not been a systematic test of whether a single group has contributed to case outcomes over an entire policy area while controlling for other elements of judicial decision making. Additionally, the degree to which extra-legal factors dominate a group's ability to influence judicial policy has not been explored sufficiently Finally, there needs to be an empirical test of the extent to which elements of judicial decision making affect an interest group's choice to litigate. This study examines these questions by assessing the NAACP- Legal Defense and Education Fund's (LDF) contribution to the population of 217 capital punishment cases decided in the U.S. Courts of Appeals. This article finds that when considered in light of the judicial decisionmaking context, the LDF is not a significant factor influencing case outcomes. Moreover, an interaction model suggests that the LDF's ability to affect case outcomes is controlled largely by extra-legal factors. Finally, there is no evidence that the LDF's decision to litigate follows a pattern based on this judicial decisionmaking context. These findings should prompt future scholars researching a group's litigation campaign to examine his/her subject in the framework of the judicial decision-making process instead of in isolation.
When David Truman (1951: 479) wrote that "the activities of judicial officers of the United States are not exempt from the processes of group politics," he recognized interest group litigation as a legitimate focus for political science. Despite its supposedly counter-majoritarian nature, the federal judiciary, like the popularly accountable branches, is subject to group pressure. Subsequent research has uncovered how interest groups influenced the federal judiciary by filing amicus curiae briefs in cases where the group has a stake in the outcome (Caldeira and Wright 1988: 1990; Epstein 1985; Krislov 1963; Kuersten and Songer 1994; O'Connor 1980; and O'Connor and Epstein 1982, 1983), and sponsoring cases in order to achieve a political end (Epstein 1985; Greenberg 1977, 1994; Ivers 1995; Kluger 1975; Manwaring 1962; Meltsner 1973; O'Connor 1980; O'Connor and Epstein 1984; Tushnet 1987; Vose 1958, 1959; Wenner 1982). Once it recognized interest groups as a viable part of the judicial process, the public law field began to explore the extent that interest groups influence policy outcomes in the federal judiciary. This article addresses this question and related issues by examining the NAACP Legal Defense Fund's (LDF) impact on capital punishment decisions in the U.S. Courts of Appeals.
EARLY INTEREST GROUP STUDIES
At the vanguard of interest group litigation research is Vose's (1959) study of the NAACP's campaign to end racially restrictive housing covenants. Vose forced scholars to reexamine this presumably private litigation battle as a conflict distinguished by a public interest group struggle as fierce as the ones taking place in legislatures. Although Vose focused on a political aspect of litigation-interest group activity-he still framed his analysis in the legal model, which perceives judicial decision making through the lens of legal doctrine. According to the legal model, the manner in which judges apply precedent to a set of facts and their methods of interpreting statutes and the Constitution are the principal determinants of Judicial decision making.1 For African Americans seeking housing equality, the federal judiciary was the best forum in which to wage their fight because success in that branch was not a function of political and electoral strength, fields in which they were lacking. Instead, a skillful legal argument and strategy were the major prerequisites to victory in the federal judiciary. Vose's group litigation concept was extended by studies operating under the political disadvantage theory, which held that certain groups litigate because they are handicapped in the popularly accountable branches of government. …