Public Approval of the Supreme Court and Its Implications for Legitimacy

In examining public evaluations of governing institutions, are job approval and legitimacy related? This question has dominated scholarship on Supreme Court legitimacy for decades. Conventional wisdom suggests that specific support (e.g., job approval) and diffuse support (e.g., legitimacy) are independent. Specific support captures short-term orientations based on policy alignment with the Court. Legitimacy is a long-term perspective reflecting more fundamental support for the Court as a governing institution. We challenge the paradigm that job approval and legitimacy are largely unrelated concepts. Specifically, we employ a variety of statistical techniques and panel data to show that changes in legitimacy are a direct effect of changes in public approval. Salient decisions and Court vacancies directly shape approval and indirectly shape legitimacy through their effects on approval. Longitudinal analysis confirms that changes in job approval precede and predict changes in legitimacy. These results suggest that the Court needs public approval, and its public approval is rooted in outcome-oriented perceptions of its decisions and membership. Further, sustained low levels of approval will eventually erode legitimacy and limit the Court's influence over policy. Thus, like the outwardly political executive and legislative branches, it is important for the Court to build political capital through job approval.