Exactly. Roberts only said that Congress has the power to tax; he didn't rule on the constitutionality of this particular, undefined tax. So what kind of tax is it? Oh, you say it isn't actually stipulated? For example, if it's not an income tax, then how can income levels be used to apportion the tax? Do they do this for property or sales taxes? How can Congress excuse itself from any tax?
The exemptions & waivers that were being granted by the DHHS were applicable only if the mandate had standing under the broad discretion of the commerce clause. Now it's been placed back in its proper context, which is nothing more than Congressional taxing power. But calling a tax a "penalty" is not just an exercise in semantics. Taxes have a real, legal meaning & basis. Obama wasn't just playing around for political points - his team knows what the real stakes are.
If the tax itself is ruled to be unconstitutional, Congress has the power to go back and amend it so as to conform to either the XVI or some other underlying principle (eg property taxes, tariffs, etc). So what if Congress doesn't amend, but lets a decision stand? That's right, it dies right there & then.
Is there anyone out there that gets what's happening yet?
I should add also, if it isn’t clear, that just because the taxing procedure is proper does not mean it’s constitutional. Let’s assume somehow the mandate penalty is not an illegal direct head tax. Let’s assume it’s an income tax, or whatever. Does that mean Obamacare is constitutional? no, because you can’t raise taxes for any old reason. And the spending that follows taxes cannot be justified by the power to tax without reference to what the taxes are spent on.
Taxing has to be constitutionally justified on the basis of how you’re going to spend it, too, not just on the procedure. You can only use the means of taxation for constitutionally allowable ends. That means the tax has to be in pursuance of the enumerated powers. The federal government taking over the healthcare industry is definitely NOT justified by the taxing power alone.
Of course, all of this is true for the Old Constitution. You know, the one that limited government and promoted liberty more than power. Since the “switch in time that saved nine” that Constitution is dead. See in particular the Helvering decision, which justified Social Security taxes on the basis of the “general welfare” clause, and Social Security spending on the basis of Social Security taxes. Helvering, needless to say, is up there with Dred Scott, Korematsu, Wickard, Kelo, etc. as one of the worst SCOTUS decisions ever.