Chin-Strumming on the Constitution

I think talking about “constitutional law” is 97 percent pointless, but as an intellectual exercise here’s a question from Radley Balko and an answer below the fold:

Putting aside what’s codified Bill of Rights, which was ratified after the main body of the Constitution, do you believe the Constitution puts any restrictions on the powers of the federal government?
If your answer is yes, what restrictions would those be? And what test would you use to determine what the federal government can and can’t do? I’ve written this before, but after Wickard, Raich, and now, if you support it, the health insurance mandate, it’s hard to see what’s left that would be off-limits. I mean, during her confirmation hearings, Elena Kagan couldn’t even bring herself to say that it would be unconstitutional for the federal government to force us to eat vegetables every day. (She did say it would be bad policy — but that’s a hell of a lot different.)
If your answer is no, that is, that the Constitution puts no real restraints on the federal government at all, why do you suppose they bothered writing and passing one in the first place?
To answer this seriously, I think the key point here is precisely to recall that the Bill of Rights wasn’t in the initial draft of the constitution. But that’s not because the Founding Fathers were illiberal people who didn’t care about freedom of religion or who wanted the federal government to quarter troops in people’s houses. Their thinking was that a Bill of Rights was unnecessary, because the main body of the constitution constituted a limited grant of authority that safeguarded individual liberty. Soon after, the leaders of the early republic quite rightly changed their minds and decided it would be better to add a Bill of Rights. This, along with the 14th Amendment, now serves the purpose of blocking federal action in the name of individual liberty. But even if you take the extreme view that Article II doesn’t prohibit anything other than what’s prohibited by the Bill of Rights, that doesn’t mean the original constitution created an unlimited federal government.
I wouldn’t go that extreme, but I would say that amendments 1-10 and 14 carry the vast majority of the weight of protecting individual liberty and leave the “main constitution” with the important role of establishing procedural rules for the federal government.
My counter-question to libertarians is what kind of moral (as opposed to legal) weight is the distinction between federal and state government supposed to carry. It’s clear to me that when the Radley Balkos of the world contemplate forcible vegetable-eating they’re primarily expressing concern for human freedom not for the law. And even under the libertarian theory of the commerce clause, state government is totally unconstrained in this regard. Our only defense against state-level tyranny is the Bill of Rights and, in practice more importantly, the day-to-day functioning of the political system. Does that mean freedom is dead? Does it mean freedom would be dead anyway, even if we adopted a much more hardcore view of the commerce clause?