A core case for supermajority rules in constitutional adjudication

In this article, I present a conditioned argument—also called a “core case”—for using supermajority rules in constitutional adjudication. I hold that, given some assumptions, constitutional courts should replace majority rule with supermajority rules to declare statutes unconstitutional. I assume that (i) there are substantive standards for assessing the constitutionality of legislation; (ii) given reasonable disagreement, statutes should be presumed constitutional; (iii) my claims only apply to some constitutional adjudication systems; and (iv) my claims only apply to “well-functioning democracies.” Given these assumptions, I argue that constitutional courts should use supermajority rules to declare statutes unconstitutional for three reasons: first, supermajority rules may boost judges’ accuracy more than majority rule on mathematical grounds and on deliberative grounds; second, supermajority rules may increase constitutional courts’ reputation by signaling consensus; and third, supermajority rules may embody the presumption of constitutionality of legislation. I finish by tackling some possible objections. Specifically, I tackle the concern that, under supermajority rules, too many statutes that should be declared unconstitutional would stay constitutional; the concern that supermajority rules in constitutional adjudication could be used to erode a democracy; and the concern that, under supermajority rules, some declarations of unconstitutionality that one judges as correct may not have happened.