Linda Greenhouse, the former New York Times Supreme Court reporter, does some in-depth legal commentary for the Times still on its Opinionator blog. It's worth reading. She predicted Chief Justice John Roberts' vote on the Affordable Care Act and, here, she's offering some interesting thoughts on what put Roberts in the majority. For example:
I doubt there was a single reason for the chief justice’s evolution (I know, conservatives hate that word in the context of Supreme Court justices’ ideological trajectories), but let me suggest one: the breathtaking radicalism of the other four conservative justices. The opinion pointedly signed individually by Justices Kennedy, Thomas, Antonin Scalia and Samuel A. Alito Jr. would have invalidated the entire Affordable Care Act, finding no one part of it severable from the rest. This astonishing act of judicial activism has received insufficient attention, because it ultimately didn’t happen, but it surely got the chief justice’s attention as a warning that his ostensible allies were about to drive the Supreme Court over the cliff and into the abyss. (Extraneous question: Is the liberal love affair with Anthony Kennedy — which should have ended five years ago with his preposterously patronizing opinion in Gonzales v. Carhart, upholding the federal Partial-Birth Abortion Ban Act of 2003 and suggesting that women are incapable of acting in their own best interests — finally over?)
... If Chief Justice Roberts, nearly a generation younger than Justices Scalia and Kennedy, in fact represents the old form of legal conservatism, in which the judicial role is to salvage statutes if possible rather than eviscerate them in the service of a bigger agenda, that’s a fascinating and highly consequential development.