Thank you for your nice response. To focus our dialogue, which I fear may be a little lawyerly even for the most robust SLATE readers, let me press you on the disagreement that interests me most. I'm still not convinced that the court's effort to take seriously constitutional limits on Congress' power can be reconciled with the court's effort to take seriously a jurisprudence of original understanding.
Let's look at the Lopez and Brady cases more closely. I agree that Lopez was correctly decided; but I think the court's reasoning exposes the Achilles' heel of the originalist methodology. Chief Justice Rehnquist, writing for the majority, acknowledged that the text of the Commerce Clause, which authorizes Congress "[t]o regulate Commerce ... among the several States," was originally understood to reserve to the states, rather than Congress, the power to regulate certain categories of economic activities that didn't directly affect interstate commerce--such as "production," "manufacturing," and "mining." As the national economy became increasingly complex in the 1930s, the court's effort to enforce the distinction between direct and indirect effects on commerce invalidated the New Deal and precipitated the court packing crisis. In 1937, after the switch in time, the court adopted a more expansive vision of the limits of Congress' power, holding that Congress could regulate all activities that "substantially affect interstate commerce." Applying this post-New Deal test, Rehnquist struck down the Gun Free Schools Act of 1991, on the grounds that guns in school don't "substantial[ly] affect" interstate commerce.
Rehnquist's conclusion seems right for those who believe, as you and I do, that there should be something left to the idea that Congress has enumerated (rather than unlimited) powers. Unfortunately, as Justice Thomas pointed out in his concurring opinion, Rehnquist's vision of the scope of Congress' powers, with its 1937 vintage, is impossible to reconcile with the original understanding of the Commerce Clause, which took seriously the distinction between "manufacturing" and "commerce." A true devotee of original understanding, Thomas argued at length, should turn back the clock to the good old days before the court packing crisis.
But then Thomas confronted a problem of his own. Resurrecting the pre-New Deal understanding of the Commerce Clause would invalidate virtually the entire post-New Deal regulatory state. Most of the federal buildings in Washington would have to shut down or be auctioned off to the states. Thomas is coy on the question of whether or not he is willing to bring the federal government to a grinding halt. "Although I might be willing to return to the original understanding," he says in a cryptic footnote, "I recognize that many believe that it is too late in the day to undertake a fundamental reexamination of the past 60 years." You confess that you, too, are a faint-hearted originalist. "Grinding to a halt," you say, "I always oppose." But then how do you reconcile this pragmatic concession with your purported devotion to original understanding?
Justice Scalia's opinion in the Brady case is even more awkward for originalists. You say that "Congress' powers are set forth for all to read, in the same words as when written." But Justice Scalia in the Brady case doesn't point to any constitutional text in particular, so I'm not sure which words you mean. Instead, Justice Scalia derives his vision of state sovereignty not from text but from history and tradition. As you say, he uses adjectives like "clear," "plain," incontestable," and "far outweighing any contrary indications" to describe his reading of constitutional history. But words like this are hyperbolic and unconvincing as characterizations of the early 19th-century understanding of federal commandeering of state executive authority. The existence of a vigorous historical debate between Scalia and the dissenting justices, Souter and Stevens, about whether Hamilton's or Madison's views were more widely accepted in 1789 (and how can any of them know the answer?) is obviously enough "ambiguity" to meet the threshold that led Justice Scalia, in Harmelin and other cases, to defer to the political branches.
You concede that Justice Scalia may have changed his methodology between Harmelin and Brady, and that the "burden" for establishing an uncontested historical tradition may have "shifted." But why should it shift? Isn't the point of originalism to be consistent from case to case? You go on to say that even if the burden has shifted, the Constitution should be construed with presumption against infringements of state sovereignty. But this begs the question I was pressing you to answer: What is the historical authority from which the court is deriving its vision of state sovereignty in the first place?
James Madison's vision of "dual sovereignty"? That would mean that the national bank is unconstitutional. Joseph Story's vision of "dual sovereignty"? That would deny the constitutional achievements of the Civil War and Reconstruction. The pre-New Deal understanding of state sovereignty? Then we're back to Justice Thomas' problem of bringing the federal government to a grinding halt. A post-New Deal understanding of state sovereignty? But then the jurisprudence of original intention is out the window. I can't think of any way out of these dilemmas, which is why I reluctantly conclude that the court's efforts to enforce enumerated powers and to respect original understanding simply can't be reconciled in a principled way.
One last point. You say that when courts construe federal statutes, they should presume that Congress didn't mean to violate state sovereignty. Maybe so. But there's an even more venerable presumption, especially favored by partisans of judicial restraint: Courts should presume that federal statutes don't violate the Constitution. This brings us back to the other set of questions I raised initially: How can the court's new zeal for striking down acts of Congress be reconciled with a general commitment to judicial restraint? But maybe we should save those questions for another day.