One of the early reactions I am seeing in comments to liberal blogs is that the 5-4 decision of the US Supreme Court to uphold the Affordable Care Act is some kind of reassuring sign that the conservative justices still have some respect for the legal principles that judges are supposed to operate under.
I'm far from convinced this is the case.
First: The decision was 5-4. The only surprising vote is that the 5th vote to uphold was from Roberts instead of say, Kennedy who is the usual "swing" vote these days (he's actually one of the top 10 most conservative justices since political scientists started tracking this in the 30s, but on the most conservative court in generations, he is the centre). But that still means there were four justices perpared to throw out decades of Commerce Clause interpretation, and that's just on the mandate. Were the other four prepared to declare the entire act unconstitutional? We'll see when the rulings hit the web, but I expect so. Remember, 19 out of 21 legal scholars contacted by Bloomberg news agreed it was Constitutional. When you have that level of legal consensus, you should expect an 8-1 or 7-2 ruling, not a 5-4. I'd also note here the predictions that Scalia wouldn't overturn himself from Gonzales v Raich didn't bear true. Consistency is not a hobgoblin haunting his particular mind.
Second: The ruling details I am seeing reported at SCOTUSBlog say that Roberts actually agrees the mandate is unconstitutional under the Commerce Clause power, but found it constitutional under Congress' taxation powers. So in fact we do have 5 Supreme Court justices voting to overturn 75 years or so of Commerce Clause jurisprudence.
Third: That also means there were four justices who don't even agree that Congress can impose a $500 tax on all Americans and then allow that tax to be waived if certain conditions are met (like say, providing proof of health insurance). This is remarkable legal hackery. Are these justices (Kennedy, Thomas, Scalia, Alito) also prepared to find the 16th Amendment unconstitutional?
There are various cynical ways to interpret why Roberts provided that fifth vote to uphold, and I find those much more plausible than that he suddenly found his legal conscience. Taking this as any kind of sign that the Roberts court puts legal principles first and foremost in its decisions would be a mistake.