Signaling the Turn: The Supermajority Requirement and Judicial Power on the Constitutional Court of Korea

In South Korea, a vote of at least six justices (out of nine) is required for the Constitutional Court (CCK) to declare a law unconstitutional. This supermajority requirement can lead to the odd situation in which a law stands despite a majority of five justices ruling it unconstitutional. In almost every other high court in the world, rulings of unconstitutionality of legislation are based on a simple majority. While one of the original rationales for the heightened voting requirement on the CCK was to curtail the power of the Court, this Article argues that it has had the unintended consequence of opening up other avenues of influence and power projection for the Court. In particular, the supermajority requirement has expanded the judicial signaling powers of the CCK, allowing the Court to directly and indirectly communicate and telegraph to lower courts, political actors, and the general public the direction of its jurisprudence. This has, in turn, strengthened the CCK’s authority and democratic legitimacy by muting accusations of judicial activism and encouraging a more gradual and incremental approach by the CCK to some of the most important and controversial social and political issues facing the country. This Article presents an original dataset of the CCK’s 4:5 decisions and examines a case study of the CCK’s adultery law jurisprudence, which illustrates the evolution of the Court’s view on the controversial law in South Korea and how the supermajority requirement allowed the CCK to gradually move towards the decriminalization of adultery in the country in line with changing social and legal norms.