The Polymorphic Principle and the Judicial Role in Statutory Interpretation

[We decline to] establish within our jurisprudence, beyond the power of Congress to remedy, the dangerous principle that judges can give the same statutory text different meanings in different cases. -Clark v. Martinez, 125 S. Ct. 716, 727 (2005) (Scalia, J.). I. Introduction The Supreme Court's statutory interpretation cases present an ongoing clash among methods of statutory interpretation-a clash that reflects a larger dispute over the proper judicial role in our system of government. On one side, the textualists tend to prefer mechanical, rules-based methods of interpretation that, at least ostensibly, minimize the role of judicial choice in the interpretive process.1 The other side, often (though not invariably) in the name of implementing congressional intent, prefers a more flexible, standards-based approach, which calls upon courts to make intelligent choices and, on appropriate occasions, to deviate from the most straightforward reading of statutory text in order to reach the most appropriate result.2 In this clash among interpretive methods, the textualists recently won another battle. Indeed, their victory was unusually powerful. Not only did Justice Scalia convince the Supreme Court to resolve a case on textualist grounds, he convinced six other Justices to join an opinion stating that a particular textualist rule of statutory construction is so strong that it must always apply; courts lack power to deviate from it. The case, Clark v. Martinez,3 turned on the question of whether a single term in a single statutory provision must always have a single meaning. If, for example, a statute takes the form, "if (A or B), then C," must C have the same meaning in cases involving A as in cases involving B? In Martinez, the Supreme Court said the answer is always yes.4 Like so many issues of statutory interpretation, this seemingly simple question implicates the largest issues, both of statutory interpretation and, ultimately, the proper judicial role in our system of government. Martinez is notable on two levels: first, for its creation of a new and unique canon of statutory construction, and second, for what it says about the Supreme Court's understanding of the judicial role. This Article explores Martinez on both levels, using the case as a window into the larger questions of statutory interpretation and the separation of powers. First, the Article explores whether there is really a canon of statutory construction that requires courts to determine that a single phrase in a single statutory provision always has a single meaning-a canon that this Article will refer to as the strong unitary principle. Scholars have long considered the canons of construction as a fruitful field of study,5 but the question of whether courts actually employ the strong unitary principle has received but little attention.6 In Martinez, however, the Supreme Court not only determined that it would read the statute before it in accordance with the strong unitary principle, but it held that the principle must always apply.7 The Court asserted that any contrary interpretive approach would be "novel" and "dangerous."8 This Article first shows that the Court erred in its descriptive claim that departure from the strong unitary principle would be "novel." In numerous cases, courts, including the Supreme Court, have applied the contrary principle that a single term or phrase in a single statutory provision may have multiple meanings-an interpretive approach that this Article will call the polymorphic principle. As this Article will show, courts employ the polymorphic principle in a variety of situations, most commonly when some special rule of statutory interpretation calls for a particular construction of statutory text in one circumstance, but has no application in other circumstances.9 Courts also sometimes employ the polymorphic principle when necessary as a pure policy matter.10 The Article then takes on the Court's normative assertion that the polymorphic principle is "dangerous. …