The Nature of Supreme Court Power. By Matthew E. K. Hall. New York: Cambridge Univ. Press, 2011. 262 pp. $94.00 cloth. Merely Judgment: Ignoring, Evading, and Trumping the Supreme Court. By Martin J. Sweet. Charlottesville and London: Univ. of Virginia Press, 2010. 240 pp. $35.00 cloth.

The Nature of Supreme Court Power. By Matthew E. K. Hall. New York: Cambridge Univ. Press, 2011. 262 pp. $94.00 cloth.Merely Judgment: Ignoring, Evading, and Trumping the Supreme Court. By Martin J. Sweet. Charlottesville and London: Univ. of Virginia Press, 2010. 240 pp. $35.00 clothMatthew E. K. Hall's The Nature of Supreme Court Power and Martin J. Sweet's Merely Judgment are impressive books that considerably advance our knowledge about the implementation and impact of Supreme Court decisions. Hall frames his study as a direct response to Gerald Rosenberg's thesis that the Court (and courts generally) " 'can almost never be effective producers of significant social reform' " (xiii; 160, quoting Rosenberg 2008: 422). Moreover, Hall argues, Rosenberg's view is emblematic of the decided weight of scholarly authority on the nature of the Court's power. The Court is generally seen as a highly constrained and weak institution (13-15). By contrast, Hall finds "that the Court possesses remarkable power to alter the behavior of [other] actors in a wide range of policy issues" (160). Sweet wants to make a different argument. He claims that "political institutions enjoy considerable discretion in deciding whether and how to follow the Court, because they can often defang would be plaintiffs" (5). Obviously, both authors cannot be right. As is often the case, as between Hall and Sweet, different theoretical approaches play a part in the competing interpretations. Notwithstanding the different approaches in play here, it seems to me that for the most part, Hall is right, and Sweet is wrong, although Sweet's study is well done and informative in many ways.Like Rosenberg, Hall is committed to social scientific positivism. Through an objective case selection method (27, and Appendix I), he pinpoints no less than 57 "important" cases decided between 1954 and 2006, which he then groups into 27 issue areas for purposes of impact analysis. Hall's conception of power, like Rosenberg's, is one-dimensional: " 'A power relation, actual or potential, is an actual or potential relation between the preferences of an actor regarding an outcome and the outcome itself ' " (7, quoting Nagel 1975). Hall's study, notwithstanding its incredible scope, is limited to seeking to observe whether the Court changes the behavior of other actors in the cases in which it actually attempts to do so by striking down laws.The question is "Under what conditions is the Court powerful?" (14). The independent variables are twofold: (1) "the institutional context" of a decision, and (2) the degree of popular opposition to a decision. The first of these brings us to Hall's great insight. Vast research demonstrates that lower courts are generally faithful and reliable implementers of Court decisions (16). By "institutional context," Hall means "the distinction between Supreme Court rulings that can and that cannot be implemented by lower courts" (5). He calls issues for which the lower courts are primary in the implementation process "vertical issues," and issues for which they are not "lateral issues." He codes every case as either vertical or lateral. For popular opinion, Hall relies exclusively on public opinion data. This elegant model thus yields a two-by-two framework for inquiry. Hall hypothesizes that only very strong popular opposition in a lateral issue can defeat the Court when it intends to alter behavior, and it follows that the Court can prevail over public opposition (even very strong opposition) in vertical cases, but not lateral ones. It then remains for Hall to specify the relevant intended outcomes of the Court's decisions, and to find good data that can show us whether actors changed their behavior in response to them. Hall is well aware that his analysis is shot through with interpretation and judgment calls. To his credit, he does not try to standardize his measures across the cases, but rather clearly lays out his thinking about what research and information is available, which indicators or measures make the most sense in a given context, and so on. …