out of nine justices to find a statute unconstitutional. A study of the South Korean constitutional court counted sixty-two cases from 1987 to 2016 decided by a 4–5 vote (that is, in which five, but not more than five, justices thought the statute was unconstitutional), along with a substantial docket of constitutional cases in which the votes were not so closely divided.[90] The study does not suggest significant tensions arising in Korean law or in the conduct of the court as a result of the supermajority voting rule, although it identifies a few issues of implementation.[91] Comparative experience also indicates that a supermajority voting rule does not necessarily prevent a constitutional court from issuing important rulings finding statutes to be unconstitutional. For example, Mexico’s Supreme Court—despite operating under a rule generally requiring the vote of 8 of 11 justices to invalidate legislation—has issued a number of important constitutional rulings against the government.[92]
B. Evaluating Supermajority Voting Requirements
In this section, we begin by articulating the arguments made by proponents of supermajority voting requirements as well as those made by skeptics. We then evaluate the extent to which supermajority voting rules would achieve the goals of their proponents and identify some implementation concerns that must be taken into account when considering these proposals.
1. Goals and Risks
The principal goal of proposals for supermajority voting requirements is to make it more difficult for the Court to invalidate laws or other government actions on constitutional grounds. A supermajority voting requirement would require broader agreement among the Justices with the judgment of unconstitutionality than under a simple majority voting rule. In the view of advocates of these proposals, the Court today is not sufficiently deferential to lawmakers by historical standards; it is too prone to overturning laws and thwarting the outcomes of the democratic process.[93] Relatedly, proponents emphasize that the Court has resolved too many disputed constitutional issues by narrow 5–4 majorities, particularly in the modern era.[94] This observation sometimes centers specifically on the Court’s perceived willingness to overturn acts of Congress, while other times it is raised more generally about the Court’s resolution of disputed matters of social policy. Some proponents of these proposals view supermajority voting requirements as a bright-line, readily enforceable means of approximating the kind of deference to legislative judgment that James Bradley Thayer sought to achieve through a “rule of [judicial] administration” under which courts would invalidate congressional legislation only in cases of “clear” unconstitutionality.[95]
