Jack Balkin ponders what may account for the Roberts Court's "sudden minimalist turn." It's an interesting post, but I reject Balkin's premise. There's nothing "sudden" about the Roberts Court's minimalism. Rather, a conservative minimalism has been the defining characteristic of the Roberts Court and, as a general matter, of the two newest justices. In this regard, NAMUNDO and Ricci, are of a piece with Wisconsin Right to Life, Ayotte, Gonzales v. Carhart, NRDC v. Winter, and many other cases in which the Court either adopted a very narrow, incremental holding or avoided reaching an underlying constitutional question. While there are exceptions, the Roberts Court has been minimalist across most areas of the law -- and most (though not all) exceptions to this pattern have been more "liberal" than "conservative" (see, e.g. Boumediene, Mass v. EPA). Chief Justice Roberts and Justice Alito certainly endorsed a non-minimalist outcome in Parents Involved, but the ultimate holding of the Court was much narrower.
As I see it, the Chief Justice and (to a slightly lesser extent) Justice Alito are committed minimalists because it comports with their views of the proper role of the judiciary. They believe that narrow, incremental holdings preserve the Court's legitimacy. If I am correct, we don't need to explain the Court's minimalism in cases like NAMUNDO and Ricci. Rather, we need to explain the Court's departure from a minimalist approach -- and we may need to do that soon if (as some expect) the Court remakes the law of campaign finance when it rehears Citizens United.