The Nature of Legal Change on the US Supreme Court: Jurisprudential Regimes Theory and Its Alternatives

Jurisprudential regimes theory (JRT) posits that legal change on the U.S. Supreme Court occurs in a drastic, structural-break-like manner. Methodological debates present conflicting evidence for JRT, which has implications for the important law versus ideology debate. We confront this debate by first elaborating two alternative theoretical perspectives to JRTevolutionary change and legal stability. Our analytical framework focuses on two key substantive effects of jurisprudential categories on the Court's case outcomesrelative differences between categories over multiple time periods and longitudinal differences across time periods. Importantly, different pieces of empirical evidence can provide support for different dynamic processes. The extent to which law matters is not necessarily tied to one particular model of legal change. Empirical analysis of updated and backdated free expression data generates key findings consistent with JRT, legal stability, and evolutionary change. We discuss the implications of the results for understanding legal change and legal influence.