Landmark case on Tenth Amendment.

For the first time, the Supreme Court has held that individual criminal defendants have standing to raise 10th Amendment objections to the federal statute under which they were convicted. Before, litigants like Lopez (U.S. v. Lopez) could only argue that the statute exceeded a Congressional power (e.g. commerce clause). Now they can also argue the reserved powers arguments based on the Tenth Amendment. This case is a turning point on the issue of Tenth Amendment standing and may open the door to Court reexamination of constitutional federalism. Somewhat surprisingly, it was a unanimous opinion and the Court shows enthusiasm for consitutional federalism. " The federal system rests on what might at first seem a counterintuitive insight, that "freedom is enhanced by the creation of two governments, not one." Alden v. Maine, 527 U. S. 706, 758 (1999). The Framers concluded that allocation of powers between the National Government and the States enhances freedom, first by protecting the integrity of the governments themselves, and second by protecting the people, from whom all governmental powers are derived.

Federalism has more than one dynamic. It is true that the federal structure serves to grant and delimit the prerogatives and responsibilities of the States and the National Government vis-À-vis one another. The allocation
of powers in our federal system preserves the integrity, dignity, and residual sovereignty of the States. The federal balance is, in part, an end in itself, to ensure that States function as political entities in their own right.

But that is not its exclusive sphere of operation. Federalism is more than an exercise in setting the boundary between different institutions of government for their own integrity. "State sovereignty is not just an end in itself: 'Rather, federalism secures to citizens the liberties that derive from the diffusion of sovereign power.' " New York v. United States, 505 U. S. 144, 181 (1992) (quoting Coleman v. Thompson, 501 U. S. 722, 759 (1991) (Blackmun, J., dissenting))."





In the end, the result will probably be the same no matter what part of the Constitutuion litigants argue. It will depend on the interpretations of federalism held by any 5 Justices who agree on something. See opinion here.