In answering the “who interprets the constitution?” and “whose interpretation shall prevail” questions foundational to large literatures in both constitutional law and political science, the scholarship on constitutional review has generally focused on three competing models: judicial supremacy, legislative supremacy, and departmentalism. The former two schools argue that the buck should stop with the judiciary or the legislature, respectively, while not necessarily excluding other branches in the process. The latter, in contrast, essentially treats each branch as, in the words of political scientist Keith Whittington, “an equal authority to interpret the Constitution in the context of conducting its duties… [because] each branch of government has its own, non-overlapping set of interpretive responsibilities.”
What this massive and important debate has generally overlooked heretofore, however, is the prospect of a fourth model: de facto executive supremacy. The theoretical literature has also neglected a particularly compelling real-world case that suggests its viability: Japan’s Cabinet Legislation Bureau, at least under some conditions. Indeed, for 70 years Japan’s postwar CLB has exercised extraordinary influence over constitutional review in the world’s third largest economy. Throughout this period, it has acted as the de facto supreme interpreter of the constitution and draft statutes, despite the existence of a court explicitly empowered by Japan’s Constitution to do so.
By introducing Japan’s CLB to this important interdisciplinary literature, emphasizing the distinction between law in books and law in action, and comparing the CLB with France’s Conseil d’État and the U.S. Office of Legal Counsel, this article highlights the important role executive institutions can play in the law-making process in both theory and practice, discusses several preliminary implications of de facto executive supremacy as a “fourth” model of constitutional review, and calls on scholars to continue the debate. Several potentially fruitful avenues for future research related to the “whose interpretation shall prevail?” question, in particular, are to broaden the conventional scope of analysis in the study of constitutional review as a whole, and to conduct more theoretical, empirical, and normative research specifically on the prospects for de facto executive supremacy as a fourth model.