Although the Supreme Court decides dozens of cases every year, it has never decided how to decide those cases. That is, the Court has never adopted a governing approach to constitutional interpretation. Instead, the justices seem to bounce from one method to the next, even when considering the same subject matter. What explains this methodological pluralism? Why doesn’t the Court consider itself bound under the doctrine of stare decisis not only to follow the substantive results of earlier constitutional cases, but also the methodological tools it used in getting there?

Chad Oldfather has a new paper on SSRN that explores the answers to these questions, Methodological Pluralism and Constitutional Interpretation. Here is the abstract:

This article takes up a significant yet surprisingly overlooked question: What accounts for the Supreme Court’s lack of methodological uniformity in constitutional interpretation? The question can be phrased in other ways: Why do strong methodological pronouncements in one case go unfollowed and unacknowledged in the next? Why, to use an example, does the originalist analysis of District of Columbia v. Heller not create a presumption that subsequent Second Amendment cases must also be analyzed via an originalist approach?

An easy answer suggests itself — the justices simply do not want to bind themselves to someone else’s preferred methodology. They hold strongly divergent views, and advocate on behalf of those views in their opinions. Each justice might be willing to adhere to a single approach, but only so long as it is the one he or she favors.

This easy answer turns out to be, at best, incomplete. There are many respects in which the Court does adhere to its past methodological choices, such as with Chevron deference or the tiered-scrutiny framework. This adherence is both unremarkable and, more generally, consistent with the application of stare decisis, which, properly understood, entails being bound by some past court’s preferences. Given that, we might imagine that stare decisis ought to apply to broader interpretive commitments. Indeed, a recent wave of scholarship has argued in favor of the application of stare decisis to the process of statutory interpretation, while at the same time demonstrating that a number of state courts have achieved methodological uniformity in that domain. Along the way, several of these scholars have suggested that their arguments might apply to constitutional interpretation as well.

In attacking these questions, this article attempts, first, to unpack the relationship between stare decisis and interpretive methodology, and to understand when stare decisis will apply to methodology and when it will not. It concludes that, at least at the broad level of determining constitutional meaning, stare decisis and interpretive methodology are an inherently unstable combination. The attainment of methodological uniformity, it turns out, is better analyzed and understood in terms of consensus. Simply put, large-scale methodological uniformity results not from the doctrinal pressure of stare decisis, but rather as a product of a settled understanding that a given method is the appropriate way to engage in legal reasoning.

Second, the article explores explanations for the methodological pluralism that characterizes the Court’s decision making. That pluralism may be a product of a tacit consensus that pluralism is the most legitimate approach to constitutional interpretation. But it may also be a default position reached due to the lack of any mechanism for forcing consensus, or the product of external, political limitations on the Court’s ability to consistently follow the logic of any single methodology. More likely still is the possibility that each of these explanations is at least partially correct.