Chief Justice Roberts's Health Care Decision Disrobed: The Microfoundations of the Supreme Court's Legitimacy

The 2012 challenge to the Affordable Care Act was an unusual opportunity for people to form or reassess opinions about the Supreme Court. We utilize panel data coupled with as-if random assignment to reports that Chief Justice Roberts's decision was politically motivated to investigate the microfoundations of the Court's legitimacy. Specifically, we test the effects of changes in individuals' ideological congruence with the Court and exposure to the nonlegalistic account of the decision. We find that both affect perceptions of the Court's legitimacy. Moreover, we show that these mechanisms interact in important ways and that prior beliefs that the Court is a legalistic institution magnify the effect of updating one's ideological proximity to the Court. While we demonstrate that individuals can and did update their views for multiple reasons, we also highlight constraints that allow for aggregate stability in spite of individual-level change.