A Spatial Model of Roll Call Voting: Senators, Constituents, Presidents, and Interest Groups in Supreme Court Confirmations

Abstract

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.We test a spatial model of Supreme Court confirmation votes that examines the effects of (1) the ideological distance between senators' constituents and nominees, (2) the personal ideologies of senators, (3) the qualifications of the nominee, (4) the strength of the president, and (5) the mobilization for and against nominees by interest groups. The data consist of the 1,475 individual confirmation votes from the 1955 nomination of John Harlan until the 1987-88 nomination of Anthony Kennedy (voice votes excluded). All of the above factors significantly affect confirmation voting. The model explains 78% of the variance in senators' decisions, predicts 92% of the individual votes correctly, and predicts all of the aggregate outcomes correctly. IntroductionThis paper examines a spatial model of roll call voting on Supreme Court nominations from John Harlan (1955) to Anthony Kennedy (1988). We approach roll call voting from much the same perspective as proponents of the new institutionalism who have adapted the spatial theory of voting to the roll call setting (Krehbiel and Rivers 1988). We explain below why we believe this approach is particularly promising. But we address the questions raised in recent roll call studies and the literature on representation in legislatures more broadly by considering the impact of constituent desires, interest group pressures, presidential power, and the personal ideologies of legislators on roll call votes. We focus on voting on Supreme Court nominees, which supplies a tractable setting for examining these questions. The model builds on our previous work (Cameron, Cover, and Segal 1990), in which constituency ideology is measured inferentially using scores developed by the Americans for Democratic Action (ADA). Our new model represents an This content downloaded from 128.255.6.125 on Mon, 20 Jun 2016 15:21:02 UTC All use subject to http://about.jstor.org/terms A SPATIAL MODEL OF ROLL CALL VOTING 97effort to measure constituency influence more directly and to purge the ADA scores of senators' personal ideologies. In this model selected state-level presidential election results are used to measure constituency ideology. We then add an explicit measure of the effect of senators' personal ideologies in addition to the purified constituency measure of the previous model. This model further extends our original work by offering a more complete specification of how the president affects the confirmation process and by incorporating interest group activity into the model as a factor that influences senators' votes. Ideology, Constituents, and Roll Call VotingWithout slighting other approaches, we start our examination of roll call voting with those studies t...

Interest groups: A survey of empirical models that try to assess their influence

“…They take state per capita membership as a measure of the strength of the influence activity and show that these interest groups were effective in influencing votes of representatives. Segal et al (1992) examine senators' vote on sixteen nominations for the U.S. Supreme Court. The number of organized interest groups presenting testimony for and against the nominee at the Judiciary Committee 19 See Grier et al (1990) and Grier and Munger (1993).…”

“…Bronars and Lott, 1994). 57 See Bender (1994), Jackson and Kingdon (1992), Lott and Davis (1992), and Segal et al (1992). In particular, by employing the two stage procedure the impact of ideology is likely to be overstated and, thus, the impact of other factors (interest groups) is likely to be underestimated.…”

Outsider Participation and Influence in Judicial Confirmation Hearings, 1979-2004

“…Many have focused on the involvement of organized interests in the confirmation of Supreme Court justices, finding that interest group lobbying has an influence on confirmation votes in the Senate (see Caldeira and Wright 1998;Segal, Cameron, and Cover 1992;Segal and Spaeth 1993). Others have focused attention on the activities of organized interests in the selection and confirmation of lower federal court judges (Bell 2002a(Bell , 2002bCohen 1998;Scherer 2005;Scherer, Bartels, and Steigerwalt 2007).…”

“…When interest groups do participate in the confirmation hearings of Supreme Court or lower court nominees, however, their involvement has been found to have an influence on both delay in the confirmation process and the likelihood of confirmation success (Bell 2002a(Bell , 2002bCohen 1998;Segal, Cameron, and Cover 1992;Segal and Spaeth 1993). Thus, interest groups may be allowed to participate in a formal capacity in the confirmation hearing process in order to provide senators with information useful to the confirmation decision.…”

The Nominations Presidents Make: Appointing Supreme Court Justices

“…Some studies have tried to model the nomination and/or confirmation process in largely ahistorical terms by using regression analysis and other sophisticated statistical techniques (e.g. King 1987;Ruckman 1993;Segal 1987;Segal, Cameron, and Cover 1992;Ulmer 1982). Other works have been more historical in their approaches, focusing on the chronology of appointments (e.g.…”