Justice Stephen Breyer issued the opinion for the court, joined by Chief Justice John Roberts, Justice Ruth Bader Ginsburg and Justice Sonia Sotomayor. Justice Clarence Thomas wrote separately, concurring in the judgment. Justice Anthony Kennedy dissented, joined by Justice Samuel Alito. Justice Elena Kagan also dissented separately.
Not only did the court not split along traditional liberal-conservative lines in deciding Luis, it also did not split along the formalist-pragmatist lines that sometimes divide the court in cases concerning the rights of criminal defendants. Insofar as we see a formalist-pragmatist split, it appears to be between Breyer’s plurality opinion, which adopts a balancing approach, and Thomas’s opinion concurring-in-the-judgment, which embraces a more formalistic analysis and bright-line rule based upon the constitutional text and common law understanding.
Kennedy’s dissent argues that the majority opinion conflicts with prior court precedent and could create perverse incentives for criminal defendants. Kagan’s separate dissent likewise notes the conflict between today’s decision and prior precedents, but limits her dissent to that. Whereas Kennedy seems to embrace the wisdom of prior cases, Kagan finds them “troubling” but argues that they should control the outcome since the petitioner here did not ask the court to reconsider those holdings.