Timothy P. O'Neill has an interesting piece on the "Thayerism" school of heavy deference to legislative judgments that may have motivated Justice Roberts's opinion in NFIB v. Sebelius. One can disagree with it, but it is a fundamentally conservative form of jurisprudence; as I argued in June, you can be unhappy that Roberts takes judicial restraint to such levels, but you can't accuse him of being a Souter.
While O'Neill focuses on Justice Harlan, Justice Roberts's own jurisprudence already gave hints of this approach: Free Enterprise Fund, NAMUDNO, and Wisconsin Right to Life, in hindsight, show the same tendency to err on the side of deference to the legislature. (See also Adler @ Volokh.)
(Apologies to Professor O'Neill for originally misspelling his name.)