As I indicated at the end of my last post, I think that the broader question on which I part company with political scientists Lee Epstein, Christopher M. Parker, and Jeffrey A. Segal is whether and how modern “political science,” as applied to judicial decisionmaking, might ever be a worthwhile field of endeavor. Let me explain.
1. I’ll start with Matt Franck’s “short history” (from this book review) on how political science “lost its way” (underlining added):
Political science as an organized, modern academic discipline has existed for a little over a century. For about the first half of its existence, public law was a vitally important interest of the discipline as a whole…. In the early twentieth century, pioneering political scientists like Edward Corwin examined the impact of constitutional jurisprudence on American civic life, and along the way proved themselves every bit the equal—often the superior—of constitutional law scholars in history departments and law faculties when it came to the analysis, critique, and uses of legal reasoning. What Corwin’s generation understood was that the most important question about every Supreme Court decision is also the most interesting question to the ordinary citizen, to the student, and hence to the scholar as well—i.e., was it rightly decided? But then, like every ordinary citizen, the scholars of Corwin’s generation believed or appeared to believe that the Constitution has a meaning of its own, independent of the passions of students, the interests of advocates, and the inclinations of judges. Legal reasoning, therefore, was actually possible.…
The behavioral revolution of a half-century ago, which brought fully into daylight the implications of positivism in political science, gave birth to the first generation in public-law scholarship of what is now known (and still going strong) as the “attitudinal model.” More or less explicitly rejecting the possibility that legal reasoning and legal principles were themselves important independent variables in judicial decision-making, the judicial behavioralists undertook to demonstrate, through the application of quantitative empirical methods, that public law was not so much the shaper of political life as the plaything of ideological, partisan, and personal motivation on the part of judges. The complete neglect of legal reasoning, and the near-total exclusion of legal principle as a causal force in judicial decision-making, represented a classic instance of begging the question.…
2. The study by Epstein, Parker, and Segal on in-group bias is a typical example of the attitudinal, or behavioralist, model. The authors never even ask whether a particular Supreme Court decision they code might be rightly decided. If a ruling, say, is unanimous for a speaker whom they code to be conservative, that ruling instead ipso facto provides evidence for them that the conservative justices have indulged their in-group bias and that the liberal justices have overcome theirs. (And vice versa, of course, for unanimous rulings for liberal speakers.)
When Epstein, Parker, and Segal compile their simplistic binary codings, they generate seemingly sophisticated tables replete with statistical measures, to the third decimal place, of mean, standard deviation, Bayesian credible intervals, and more. The only appropriate response, I would suggest, is to laugh out loud at the pseudo-scientific absurdity.
Epstein, Parker, and Segal purport to assess whether the voting pattern of a justice is “statistically significant.” But without establishing how the ideal justice should rule in the various cases—an enterprise that would require the exercise of legal judgment and that would, of course, be highly contestable—they have no sound objective benchmark against which to measure an actual justice’s voting pattern. They implicitly assume that the ideal justice would vote for liberal speakers at the same percentage level as for conservative speakers. That assumption in turn presupposes that the cases in which claims of liberal speakers and conservative speakers arise are equally meritorious. But there are various reasons, as I’ve briefly discussed, why that assumption may be wrong (in either direction). For example, if a justice believes that pornography receives little or no protection from the First Amendment, and if pornographers are disproportionately coded as liberals, pornography cases would operate to generate a disparity in the justice’s voting pattern, even though the disparity has nothing to do with speaker-favoritism or speaker-hostility.
3. In sum, I’m very skeptical that political scientists can generate any valuable insights about judicial decisionmaking simply by coding the votes of Supreme Court justices in particular cases and spewing out statistics. To be clear: I am not taking the position that statistical analysis of voting patterns is necessarily worthless. In particular, I’m open to the possibility that it might suggest avenues for further exploration. But that further exploration, if it’s going to be fruitful, will have to involve the (sometimes) difficult and (often) contestable work of engaging in legal reasoning.