The Alien Tort Statute (ATS), (222) which has survived without amendment since (1789), presents modern courts with an analogous interpretive conundrum. The ATS confers federal court jurisdiction in "civil action[s] by an alien for a tort only, committed in violation of the law of nations." (223) In the words of one commentator, it "was enacted ... as a national security statute" to afford remedies to British merchants, creditors, and others for injuries "for which the United States bore responsibility under contemporaneous international law." (224) In Sosa v. Alvarez-Machain, (225) in which a modern plaintiff sought to rely on the ATS to recover for international human rights violations occurring outside the United States, the Supreme Court agreed unanimously that the ATS was jurisdictional only; it neither created a cause of action nor conferred an independent authority on federal courts "to mold substantive law." (226) Yet the ATS clearly presupposed not only the existence of "the law of nations," but also the availability of some source of law--which may have been "general" law--authorizing tort actions in cases involving breaches of the law of nations. So reasoning, Justice Souter's opinion for the Court held that federal courts could entertain suits under the ATS for torts that would have been actionable under the ATS at the time of the ATS's enactment. (227) Over the protest of Justice Scalia, joined by Chief Justice Rehnquist and Justice Thomas, (228) Justice Souter also held that no development subsequent to (1789) had "categorically precluded federal courts from recognizing a claim under the law of nations as an element of [judge-made federal] common law." (229)
Further perplexities and disputes surrounding modern doctrines involving federal common law may similarly fall within the category of cases in which judges must take account of changed historical circumstances in order to resolve cases with constitutional dimensions. As acknowledged in Sosa, and contrary to many a law student's misimpression, Erie did not abolish the category of federal common law, but only of federal general common law. (230) Today there are important enclaves of federal common law, but it is real federal law, binding on state courts under the Supremacy Clause as much as on federal courts. (231) Given changed historical understandings, the Supreme Court now must wrestle with a number of issues involving the current status of pre-Erie cases that crafted or relied on "general" common law rules of decision in a universe in which a modern federal common law rule of decision would preempt state law and bind state courts under the Supremacy Clause. The lively debates over whether, and if so when and why, customary international law forms a part of the federal common law of the United States turn largely on issues of this nature. (232)
L. Historical Trend Lines Bearing on Intra-Temporal Coherence
I referred earlier to the pertinence of Founding-era legal culture in determining how constitutional and statutory language should be read and how judges should decide cases. (233) But understandings of the appropriate judicial role, and surrounding conceptions of proper interpretive methodology, change over time. When the trend line exhibits disparities between the jurisprudential or methodological assumptions exhibited in past judicial decisions and those that have more recently gained approval, questions emerge about whether norms of current practice can justify the revision of prior precedents that have not otherwise proved unworkable. Resolving these questions requires a mix of historical and normative analysis.
A recent example of doctrinal reform to reflect changed understandings of appropriate constraints on judicial decisionmaking involves "prudential" standing doctrine. As formulated by the Supreme Court in cases decided during the twentieth and early twenty-first centuries, the doctrine of standing involves proper parties to litigate legal issues in federal court. (234) Emphasizing standing's roots in the separation of powers, a number of past decisions insisted that standing has a prudential as well as a constitutional component. (235) 236 As the Supreme Court pointed out in Lexmark International, Inc. v. Static Control Components, Inc., (236) however, the notion that the federal courts could make prudential decisions not to decide cases within their statutory jurisdiction coheres badly with repeated affirmations in other contexts that the federal courts have a virtually unflagging obligation to exercise all of the jurisdiction that the Constitution and laws of the United States confer on them. (237) In light of that historically sharpening disparity, (238) Lexmark not only trimmed one branch of prudential standing doctrine, but also intimated that further retrenchment may lie ahead. (239) More generally, I think it fair to say that the Court's unanimous decision in Lexmark reflects an uncontroversial assumption that recent history and precedent, including precedent involving appropriate interpretive methodologies, sometimes requires a rethinking--which necessarily blends historical with normative considerations--of previously settled doctrines.
The point of the foregoing summary is fivefold. First, historical inquiry and analysis are pervasive in constitutional law, as demonstrated by a number of cases and issues--most of which have not been thought to raise any large question of methodological principle--at the center of the federal courts canon. Second, the types of historical inquiry and analysis that bear on constitutional adjudication are highly diverse, by no means limited to questions about the original understanding or original public meaning of constitutional language. Third, the original public meaning as it features in constitutional analysis is frequently indeterminate in its application to particular cases. As a result, conclusions about the proper application of law to resolve particular issues often cannot rest directly on any historically discernible fact--for the discernible facts stop short of establishing the necessary conclusion--but instead must reflect judgments about how uncertainty or disagreement would best have been resolved in the historical past, in a sense of "best" that cannot be wholly value-free. Fourth, in cases of conflict between the decisions that judges otherwise would render in light of evidence of the original public meaning and other historically grounded considerations (such as, for example, liquidated meaning, historical gloss, tradition, or stare decisis), the judicial view of the most reasonable application of the original public meaning does not always prevail. Instead, the Justices make judgments that blend historical with normative considerations. Fifth, even in cases in which judges and Justices perceive a conflict between the original meaning of constitutional language and some other history-based consideration, few if any Justices of the Supreme Court have consistently maintained that the original meaning--the identification of which may itself require normative judgments--should always determine judicial outcomes. (240)
II. PRELIMINARY EXPLANATIONS
Before inquiring whether most or all of the historical phenomena that matter in constitutional adjudication ought to matter, it will be useful to explore how and why the current state of affairs has developed. Because the leading causal factors emerge so nearly self-evidently from the Part I's catalogue of types of historically rooted reasoning, I shall be very brief.
The Fixation Thesis
In thinking about how a diverse set of historical phenomena can bear on constitutional analysis, we can best begin with "the fixation thesis" that, according to Professor Lawrence Solum, represents the central tenet of originalist constitutional theory: events involved in the drafting and ratification of a constitutional provision determine its meaning. (241) Although Solum advances the fixation thesis as a pillar of constitutional originalism, either a weak version of that thesis or a weaker analogue thereto defines a consensus starting point among constitutional analysts. With rare exceptions, all agree that the Framers' intent, the original public understanding, or the original public meaning of constitutional language (to the extent that it can be ascertained) at least provisionally fixes constitutional meaning and that it also continues to fix constitutional meaning into the distant future, absent some significant consideration dictating a different conclusion. (242) The two main disagreements involve the determinacy with which historical evidence can establish an original meaning in some cases (243) and the questions of whether and when a "fixed" meaning might become unfixed as a result of stare decisis, historical gloss, traditional practice, or changed historical circumstances. But it is important to recognize common ground. If, for example, a dispute arose about the meaning of a constitutional amendment that had been ratified a year earlier, the notion that courts could reject the original understanding or original public meaning and decide on the basis of some other consideration would seem preposterous.
Accordingly, all of the forms of historical evidence that bear on the original intent, original understanding, or original public meaning possess relevance to at least some interpreters. Given what I have just said about a virtual consensus acknowledging the relevance of Founding-era history, here I refer more qualifiedly to "at least some interpreters" because, as Part I emphasized, the original intent, original understanding, and original public meaning represent different objects of historical inquiry. (244) Even among originalists, debate surrounds the question of their relative pertinence. Strikingly, moreover, some participants in constitutional debate may have no consistent, settled view on the question of exactly...