Oh Yeah, That's Some Commerce Right There

Brad DeLong has this to say about Sam Alito's ruling that private possession of a machine gun didn't seem to fall under the federal Interstate Commerce power:

I genuinely don't understand how machine guns are not part of "economic activity." Wouldn't most people who use or threaten to use machine guns use them to get money–often through transactions that cross state lines?

I hope that wherever the Constitution-in-Exile is in exile, it is a warm, happy, peaceful friendly place. Because I want it to stay there for a long time.

DeLong gets props for a good headline ("The Constitution in Exile Orders a Mojito") but less so for the logic here. First, what's the evidence for the premise? Most people who'd own machine guns would use them "to get money" (presumably criminally)? Really?

But it's actually the inference that follows from this (or, rather, the assumption that makes the inference work) that's really striking: If X could be used to obtain money through an interstate transaction, mere possession of X falls under Congress' commerce power. Now, it should be pretty obvious that almost anything qualifies under that definition. The clothes on my back? I could sell them on Ebay. The books on my shelf? I surely might quote from any of them in an article for Reason (which cuts my paycheck at HQ in California). Just about everything in my home, though not in what you might call kinetic commerce, is surely at least potential commerce. The thing is, of course, DeLong's right: Hoary precedent supports that view, and if he "genuinely doesn't understand" how someone could think all those Xes weren't supposed to be subject to federal regulation by the Commerce Clause, well, he's got the mainstream view. And somehow, it's still kind of mindblowing to be reminded of this.