Does legal doctrine genuinely constrain the choices Supreme Court justices make? Do justices' ideological preferences dominate their decisions? The "law versus ideology" debate provides conflicting answers to these questions. What is missing is a fuller accounting of the capacity of legal doctrine to constrain justices from acting on the basis of their ideological preferences. The current project aspires to provide a comprehensive theoretical and empirical examination of legal doctrine's impact on judicial decision making. Depending on how presumptive legal doctrine is of an outcome, some legal rules and standards may constrain ideological discretion, while others may actually enhance such discretion. The current research tests competing models and hypotheses regarding how variation in the presumptiveness of legal doctrine influences ideological discretion and hence the degree of ideological voting. The project will examine justices' voting behavior in a large number of cases within multiple legal issue areas spanning the prior sixty years. The data will be analyzed using multi-level statistical models.
The findings of this research will facilitate a richer understanding of judging. More broadly, the insights regarding how and when the "rules of the game" constrain political actors are informative in better conceptualizing the role of courts in the democratic process.
Does law matter? In the U.S. Supreme Court, how law matters is crucial for understanding both how the justices vote in particular cases and the policy implications of a Supreme Court ruling. Moreover, it is important to grasp how law changes over time and how such changes affect future rulings. This project has examined -- and will continue to examine -- how and why legal doctrine in the U.S. Supreme Court both changes over time and constrains justices from acting on the basis of their ideological preferences (i.e., "ideological voting"). In the area of free expression law, I have found that legal doctrine constrains ideological voting depending on how prescriptive the applicable legal standard is. When the Court applies a highly prescriptive and rights-protective standard like "strict scrutiny," such constraint occurs. When the Court applies more intermediate levels of scrutiny or prescribes deference to the government, legal doctrine becomes less constraining, justices have more discretion, and ideological voting is elevated. I have also examined how legal change occurs on the Court, after having collected updated data in the free expression issue area. A prominent theory in political science, jurisprudential regimes theory (JRT), posits that legal change in the U.S. Supreme Court occurs in a drastic manner as a result of a landmark ruling. In contrasting this perspective with two alternative models of legal change -- evolutionary change and legal stability -- I have found that the effects of legal standards on the Courtâ€™s case outcomes can be consistent with each of the three dynamic processes. Importantly, different pieces of empirical evidence can provide support for different dynamic processes. The extent to which "law matters" is not necessarily tied to one particular model of legal change. For instance, case outcomes for which a rights-protective and prescriptive standard are applied are quite stable over time in the liberal direction. They do not change drastically as a result of a landmkark precedent or as a result of membership change in the conservative direction (during the early 1970s), thus indicating a significant degree of legal constraint. I am in the process of analyzing legal change and constraint in the area of Fourth Amendment search-and-seizure law in the Supreme Court, after having gathered additional data for this issue area. One of the puzzles this research addresses is what happens once the Court drops the degree of rights-protectiveness such that the legal standard prescribes a great degree of deference to the police in searches and seizures. What constrains the Court? Some preliminary results show that legal factors that used to matter in the area of warrantless searches -- place of search, certain legal exceptions -- no longer influence case outcomes. It begs the question of what exactly does influence case outcomes? In this case, lowering the legal standard (reducing the degree of rights-protectiveness) leaves little room for the law to influence case outcomes because justices have such wide discretion to decide on the basis of their ideological preferences. Taking free expression and search-and-seizure issue areas together, an implication is that raising the level of scrutiny to "strict scrutiny," a highly prescriptive standard, seems to constrain ideological voting and case outcomes, as in free expression. But minimizing the level of scrutiny below strict scrutiny, as in search-and-seizure, seems to grant justices greater discretion and enhances the degree of ideological voting. In sum, understanding the Supreme Court's use of legal doctrine is not strictly academic. Legal rules have significant real-world implications for policymaking in a democracy. The degree to which a legal doctrine protects a constitutional right has significant implications for the conditions under which democratic majorities can legislate on an issue. It is therefore crucial to understand the foundations and consequences of legal doctrine and legal change in the context of Supreme Court decision making.