When I have some more time I want to talk a lot about David Sloss' "Polymorphous Public Law Litigation: The Forgotten History of Nineteenth Century Public Law Litigation." Cribbing now from the abstract:
Recent debates about popular constitutionalism and judicial supremacy have focused on the question of who interprets the Constitution. This article reframes the debate by asking what legal sources courts apply to protect individual rights from government infringement. Throughout the nineteenth century, federal courts applied a mix of international law, statutes and common law to protect fundamental rights and restrain government action. This article uncovers the forgotten history of nineteenth century public law litigation.
Professors Post and Siegel have advocated “policentric constitutional interpretation,” wherein the Supreme Court shares authority for constitutional interpretation with other actors. By analogy, this article introduces the concept of “polymorphous public law litigation.” Under the polymorphous model, instead of fixating on constitutional law as the dominant public law discourse, courts apply international law, statutes, and common law — and occasionally constitutional law — to decide public law controversies. The article demonstrates that nineteenth century federal courts applied a polymorphous model of public law litigation.
During the twentieth century, the polymorphous model was supplanted by a constitutionalized model of public law litigation, wherein courts rely primarily on constitutional law to decide public law cases. The process of constitutionalization exacerbated the tension between judicial review and popular sovereignty. When the Supreme Court applies constitutional law to decide a case, the Court does not merely decide the case; it also creates or modifies a legal rule that is not subject to revision by legislative majorities. In contrast, when the Court applies other types of law, Congress or state legislatures retain the power to modify the controlling legal rule. Hence, revival of a polymorphous model would help mitigate the tension between judicial review and popular sovereignty.
While I don't use fancy words like polymorphous, I agree that Sloss is exactly right in portraying the diverse sources that the Supreme Court looked to in deciding public law questions. This is an important quantitative exploration of the ways that antebellum Americans brought a lot of sources to bear on key issues, such as the relationship between state and federal power, particularly as it related to slavery. In a world with a relatively small number of sources, antebellum Americans perhaps unsurprisingly turned to treatises on international law as well as treatises on political philosophy, history, and economics. The diversity of sources for the Supreme Court correlates with the diversity of sources that politicians (often lawyers) used in public addresses and on the floor of Congress. This testifies again to the importance of constitutional ideas in public debate.
If I could add one other more precise comment here -- one of the reasons that I think the Taney Court (and southerners more generally) used international law arguments so frequently is that the analogy worked well for southern states; they liked the idea that other states (perhaps stronger, northern ones) could not impose their anti-slavery rules on southern states. The equality dignity of sovereigns was useful for southerners who wanted their states to be as free as possible from control by northern states. (My co-author Stacey Gahagan talks about this some, as I recall, in her work on Vattel.) (I feel this in particular about figure 3, which shows a dramatic decrease in citations to international law after 1864 -- when Taney dies.) More as I have a chance to dig into this in the detail this important article obviously warrants.