What Is a "Tenth Amendment" Claim?

Over at The Cockle Bur, Timothy Sandefur has a helpful post summarizing the interesting amicus brief that he filed last week in support of Virginia's challenge to the individual mandate in the Fourth Circuit, largely responding to (and attacking) arguments that we made in our amicus brief in support of the government in the same case. [In short, we argued that Virginia doesn't have standing; Tim's brief argues that it does.]

I'll leave it to interested readers to decide whose brief is more convincing, but there's one fundamental analytical disagreement that I think dominates the differences in our position: The heart of the brief in support of Virgina's standing is the premise that, wholly distinct from parens patriae standing (which settled precedent denies to states in suits against the federal government), states suffer their own freestanding Tenth Amendment injury whenever Congress passes a statute in excess of its enumerated powers. Indeed, as the brief rightly notes, indviduals generally lack standing to enforce the Tenth Amendment, except perhaps as a defense in criminal prosecutions (depending on what the Supreme Court does with the Bond case it has this Term). It should logically follow that, where individuals lack standing, states don't...

Here's where I think we're talking past each other: I had always thought that there's a meaningful analytical difference, at least these days, between a "pure" Tenth Amendment claim and a claim that Congress has exceeded its Article I powers. Thus, cases like New York v. United States and Printz are examples of the former, where Congress is injuring states directly by commandeering their legislative/executive policy. Congress might have the enumerated power to enact the legislation in the abstract, but the Tenth Amendment injury is in how the law applies to the states. In contrast, cases like Lopez and Morrison aren't "Tenth Amendment" cases, since Congress isn't directly telling the states to do (or not do) anything. As Justice Douglas explained in 1941, in this context, "The amendment states but a truism that all is retained which has not been surrendered." Yes, the Tenth Amendment presumably reserves power to the states, but--in marked contrast to the commandeering cases--it doesn't inform the analysis of whether Congress has exceeded its authority. It should follow, if Massachusetts v. Mellon and its progeny mean anything, that states generally lack standing to challenge the constitutionality of legislation in this latter category, but have standing to challenge the constitutionality of legislation in the former, commandeering context.

If that distinction is correct, then I'm hard-pressed to see how the state challenges to the individual mandate fall on the pro-standing side of that line--or, if they do, how any challenge to congressional power doesn't. The short of the argument, as I understand it, is that Congress is preventing the states from enforcing their own laws on the subject, but that's always true where there's a conflict between state and federal law. Congress isn't "commandeering" states to do anything. And unlike in New York and Printz, the federal statute is directed at private, rather than state, conduct. If this is nevertheless a "Tenth Amendment" claim, what isn't?