A new argument about interpretation appeared in the twentieth century: the idea that Supreme Court justices should make their own judgments about the best national policy, and then write their opinions in language that gives the impression that the decision represents an interpretation of the Constitution. This chapter argues that decision science says that the Supreme Court justices are not well-suited for making good policy decisions, and that, if they do so, they should be transparent in their reasoning. For thousands of years, the public and its elected representatives have looked to the courts to provide answers to difficult and important issues involving interpretation, something for which judges are well-trained and well-placed to do. When that traditional process metamorphizes into pure political policymaking, the justices need to defend it as such, and not put at risk the Court’s essential role as the authoritative interpreter of legal texts.