The Volokh Conspiracy � More Hints that Roberts Switched his Vote:
Reader Stuart Buck provides more detail as to why the dissent reads like a majority opinion (see also Deborah Pearlstein at Balkanization):
1. The dissent has a whole section on severability that is completely beside the point except on the assumption that the mandate had been struck down, and now “We” have to decide whether and what to preserve of the rest of the act now that the mandate is gone.
2. Notice also that his response to Roberts is tacked on at the end, rather than worked into the body of whatever he was writing (see page 64 of his dissent). For example, one would have expected Scalia to directly take on Roberts’ application of the Anti-Injunction Act, but his brief section on that act only mentions what “the Government” argues (see pages 26-28).
3. On top of that, Scalia’s sections on the Commerce Clause and the Medicaid Expansion are just as long or longer than what Roberts writes (Scalia wrote 16 pages on the Commerce Clause and 21 pages on the Medicaid Expansion, compared to Roberts’ 16 pages and 14 pages respectively). Yet Scalia never writes in the vein of saying, “I agree with the Chief Justice’s opinion, but write to add a crucial discussion of some complexity.” His analysis agrees with Roberts, and makes essentially the same points in “We” language. There’s no reason for Scalia to do this at such length, unless his opinion is what came first.