No Shelter in Unanimity: The Limits of Consensus for Supreme Court Legitimacy
2026-06-04
Supreme Court justices sometimes strategically use unanimity in an attempt to bolster the legitimacy of a court ruling and of the court itself. Do unanimous court rulings promote legitimacy? We pair evidence from three experiments based on real Supreme Court cases (including rulings on Donald Trump’s ballot eligibility) with observational analyses of the General Social Survey (1975–2024) to examine the influence of unanimity in more realistic environments than used in prior studies. Contrary to the belief that judicial consensus signals impartiality and bolsters legitimacy, we find that unanimity has little to no consistent effect on decision approval or broader evaluations of SCOTUS. Unanimity also does not reliably improve attitudes among people predisposed to disagree with the Court’s rulings. These findings challenge assumptions about judicial strategy and raise broader questions about the role of consensus in institutional legitimacy.