Why Judges Sometimes Agree When Politicians Cannot
Headline-grabbing Supreme Court cases about affirmative action, states' rights, and abortion are often decided by narrow 5–4 majorities. One might suppose that such votes are typical of the Court's docket. Not so. About one-third of the Court's opinions in each of its recent terms have been unanimous. In these cases, the justices agree about which party should prevail and about what legal rule justifies that outcome.1 In another group of the Court's cases, the justices reach a unanimous judgment, but not a unanimous opinion: in other words, they agree about which side should win, but they differ about the best rationale for the decision.2 Together, cases with unanimous opinions and cases with unanimous judgments account for about one-third to one-half of the Supreme Court's docket in most years. Ideological divisions among the justices thus affect outcomes more rarely than one might suppose.
To be sure, many of the Court's unanimous rulings involve topics that are uninteresting or arcane, at least to the ordinary citizen. During John Roberts's and Sam Alito's first term on the Court, all nine justices agreed about the circumstances under which the Em