Hey Trende, Roberts voted with Kagan, Ginsburg, Sotomayor and Breyer! Do I need to say anything more? He’s a freaking, cowardly traitor!
Trende's point (which is an accurate one, if you read the entire decision & dissent) is that Roberts' agreement with Kagan, Ginsburg, Sotomayor and Breyer had nothing to do with the Constitutional power of Congress. All nine justices agreed that Congress has the power to impose a tax on people who do not purchase health insurance. That point is the point that expands the power of Congress
Rather, Roberts' agreement with the liberals (and disagreement with the conservatives) was not related to Congress's power to impose such a tax, but rather whether Congress did so in this particular case. That's obviously an important point within the case itself (and the outcome of the case itself is obviously important, and terrible), but it's not likely to have broader impact on future cases. The point that will likely have impact on future cases is the power of Congress to tax inactivity, and, unfortunately, on that point, all nine justices agreed.