This Article explores the concept of “judicial federalization doctrine.” The doctrine emanates from well-documented areas of federal constitutional law, including exactions, racially motivated peremptory challenges, the exclusionary rule, same-sex sodomy, marriage, and freedom of speech and press. The origin and development of these federal doctrines, however, is anything but federal. The U.S. Supreme Court has, on rare occasions, heavily consulted with or borrowed from state court doctrines to create a new federal jurisprudence. While the literature addressing the Court’s occasional vertical dependence on state court doctrine is sparse, there is a complete absence of scholarly attention studying the Court’s reluctance to horizontally consult, refer to, or cite, as persuasive authority, its own past caselaw federalizing of state court doctrine. For example, in its 1985 Batson v. Kentucky ruling, the Court established a new federal jurisprudence by adopting state court doctrines barring prosecutors’ racially motivated peremptory strikes. But the Court, notably, omitted any reference to its 1961 case, Mapp v. Ohio, where it similarly borrowed state doctrine to nationalize the exclusionary rule. Likewise, the Court relied upon state court rulings on same-sex sodomy to develop a federal constitutional protection in Lawrence v. Texasin 2003. Yet, the Court neglected to cite its analogous practice of endorsing state doctrines to develop a federal exactions standard in Nollan v. California Coastal Commission and Dolan v. City of Tigard in 1987 and 1994. When the Court federalized same-sex marriage in Obergefell v. Hodges in 2014 by following the lead of state courts, it missed an opportunity to cite its 1964 ruling in New York Times Co. v. Sullivan, a case that modeled its new First Amendment “actual malice” test based on a version formulated by state courts.The substantive rights and protections at play in each of these rulings have little, if anything, in common. But the practice of consulting state doctrine as the primary source for developing new federal jurisprudence is the same in all the cases. Indeed, with each subsequent ruling that embraced state doctrine, the Court did not cite any combination of these prior cases. In contrast, the Court has built a track record of horizontally citing to its legislative federalization cases; that is, cases where the Court consulted state law to inform federal constitutional law. Why, then, has the Court failed to articulate and organize its limited collection of judicial federalization cases into a coherent, recognizable, and authoritative doctrine? This Article explores this puzzling lacuna within the Court’s citation practices and decision-making methods and offers a variety of reasons for the Court’s preclusion of this citation method. The Article argues that the Court should formally announce a doctrine, called “judicial federalization doctrine,” that establishes a consistent practice of vertically consulting state court doctrine and that demonstrates a regular method of horizontally citing its past precedent federalizing state doctrine
