Comparing Circuits: Are Some U.S. Courts of Appeals More Liberal or Conservative Than Others?

This article investigates possible ideological differences between circuits of the U.S. Courts of Appeals. It looks at the distribution of three-judge panel ideologies on the circuits and at differences in decisionmaking patterns, testing several theoretical approaches to circuit differences: the attitudinalist approach, arguing that different judicial ideologies account for intercircuit differences; historical-institutionalist approaches that argue that circuit norms lead to differences in the proportion of conservative decisions and in the effects of judicial ideologies; and the rational-choice institutionalist argument that overall circuit preferences constrain three-judge panel decisions through the en banc process. Using a multilevel logit model, the study finds some support for the attitudinalist and historical-institutionalist accounts of circuit differences. It also finds that intercircuit ideological differences contribute comparatively little to the prediction of appeals court outcomes. Popular commentators and scholars alike frequently state (and often simply assume) that there are ideological differences between different federal appeals circuits. Currently, the Ninth Circuit receives the most attention, mainly from commentators critical of its presumed liberal tendencies: Commentator Bill O'Reilly calls it the ''wild bunch'' (2002); Senator Orrin Hatch blames it for ''judicial activism and overreaching'' and claims that it is ''out of the mainstream of both American law and culture'' (2002); lawyer and legal commentator Bruce Fein, in the Washington Times, accuses the court of ''manipulative judging at its worst'' (2006, p. A16); and on it goes. On the other side of the spectrum, the Fourth Circuit is often singled out as particularly conservative: New York Times reporter Deborah Sontag calls it ''the shrewdest, most aggressively conservative federal appeals court in the nation'' (2003:40), while legal commentator John Dean goes one step further, calling it ''the most conservative circuit court in modern American history'' (2009). Other circuits have similar reputations, though their descriptions typically create less political heat. Sunstein et al. (2006:108) summarize the conventional wisdom as they see it: ''In accordance with standard lore, the Third and Ninth Circuits are two of the most liberal, and the Seventh and Eighth Circuits are two of the most conservative.'' There are good theoretical reasons to expect the common wisdom on ideological circuit differences to be true. Different circuits ''house'' different judges with different political predispositions; circuits set their own precedent, only rarely overturned by the Supreme Court; different circuits can be expected to develop different political and jurisprudential cultures.1 Considering this, it is surprising that, while several political scientists and empirical legal scholars have investigated intercircuit differences in decision patterns and court composition in passing, the actual ideological differences between circuits have rarely been placed at the center of analysis. There is little analysis of what it means that circuits are more liberal or more conservative and of which factors influence the differences between circuits. In fact, legal researchers do not even know whether ideological circuit differences can be shown with a high level of empirical confidence. The question of intercircuit ideological differences is more important than the heightened rhetorics and political point-scoring of popular discourse suggest. From a practical perspective, if the decisionmaking in the U.S. Courts of Appeals follows ideologically identifiable intercircuit differences, then the uniformity of American law is likely to be undermined. This may not necessarily be a bad thingFintercircuit differences may reflect differences in the political cultures and socioeconomic conditions of different regions in the United States. But they may also increase legal uncertainty in a geographically mobile society. …