We'll never know. (Let me say first that I called this one wrong. I though the mandate at least was going down. Rarely so glad to be wrong.) But here's a negative look : By voting with the liberals to uphold the Affordable Care Act, Roberts has put himself above partisan reproach. No one can accuse Roberts of ruling as a movement conservative. He’s made himself bulletproof against insinuations that he’s animated by party allegiances. But by voting with the conservatives on every major legal question before the court, he nevertheless furthered the major conservative projects before the court — namely, imposing limits on federal power. And by securing his own reputation for impartiality, he made his own advocacy in those areas much more effective. If, in the future, Roberts leads the court in cases that more radically constrain the federal government’s power to regulate interstate commerce, today’s decision will help insulate him from criticism. And he did it while rendering a