"The consensus among scholars and Supreme Court practitioners is that Chief Justice Roberts is unlikely to add the fifth vote to those of the four justices in the court’s liberal wing to uphold the law. But he is said to be quite likely to provide a sixth vote should one of the other more conservative justices decide to join the court’s four more liberal members."I, too, tend to think the Chief is the swing vote. But I also think it possible Roberts might join the four Democratic appointees to uphold the Act with a 5-4 majority.
Also of note in today's Times is this op-ed from Fourth Circuit Judge J. Harvie Wilkinson, an esteemed jurist who came close to being nominated for the Court on a couple of occasions. As relevant to the ACA, Wilkinson opines that
"[i]t is tempting to shout states’ rights when deeply flawed federal legislation is enacted, but the momentary satisfactions of that exercise carry long-term constitutional costs. Badly conceived bills die a thousand political deaths — in the appropriations process, in the states, through electoral retribution, in the executive appointments of a succeeding administration and ultimately in amendment and repeal. However, if courts read the Constitution in such a way that it enables them to make Congress ineffectual, and instead to promote 50 state regulatory regimes in an era of rapidly mounting global challenges, the risks should escape no one."