Judge Roger Vinson's ruling that the individual health insurance mandate is unconstitutional seems to have surprised a lot of commentators. I'm surprised they're surprised. The ruling may be wrong--ie, it may in due course be overturned by the Supreme Court--but it is perfectly intelligible, and oral argument had already suggested he was leaning this way. The only unexpected part of the ruling was his finding that the whole law is void, on the grounds that the mandate cannot be removed from the legislation without making the entire thing unworkable. But, as the ruling says, the legal non-severability of the mandate is something that the White House and Congress had previously insisted on, so you could say it was they who demanded the ruling's all-or-nothing character.
I want the reformers to succeed, but they made things harder for themselves in another way too. Even before the law was passed and the legal challenges began, it was understood that the distinction between "tax" and "penalty" was constitutionally significant. The law could have levied a tax to cover the costs of insurance subsidies in such a way that only people who chose to be uninsured would be burdened by it. The effect would have been similar to the mandate's, but without the constitutional problem (the power to tax and spend is pretty well established). Why didn't the reformers do it that way? Partly because it would have broken Obama's promise not to raise taxes.
Message confusion has thus arisen on both sides. For legal purposes, it would be convenient for liberals to say that Obama lied: the penalty is really just a tax. Unless they are careful, conservatives may find themselves calling the president a man of his word. It's awkward.
Once you see the penalty as a penalty and not a tax, the main question that Vinson poses--if the government can force you to buy health insurance, what can't it force you to buy?--is a good one. The Supreme Court, when it gets the case, will want to find an answer--some principle that lets health reform stand while appropriately limiting the federal government's freedom of action. Voiding the law, I'm sure, is not something a majority will want to do, even if public opinion remains (moderately) opposed to the reform. Too bold. Too disruptive, especially if they take their time getting around to it. But they will want to come up with a rationale for letting the law stand that does not give the feds carte blanche. And that may not be straightforward.
(Note to puzzled Europeans. In the US, the federal government's powers, unlike the states', do not take the form of a general "police power". The powers are enumerated in the Constitution. The ability to punish people for not buying something is not, at first sight, among them.)