Originalism is in ascendance. Both in judicial opinions and in the legal academy, arguments for the interpretation of the Constitution based on its original meaning are increasingly prominent. The scholarly literature to date, however, has focused on theory. Supporters and opponents debate the theoretical merits of originalism, but rarely test their views on the merits of originalism by reference to the realities of constitutional adjudication. In science, a theory gains acceptance if it makes testable predictions that are later borne out. Whatever its theoretical merit, originalism deserves recognition as genuinely distinctive and useful approach to constitutional adjudication only if, in practice, it provides a genuinely originalist vehic...