Why? Because, according to Stephan Kinsella's interpretation of the law, the Second Amendment only forbids the federal government from banning guns (actually, that's inaccurate: the claim is more that the Second Amendment and the entire Bill of Rights are "irrelevant and redundant .")
Well, isn't Washington, D.C. under federal jurisdiction, and doesn't that mean the Second Amendment would apply? Things are not so simple. He cites approvingly Kevinn Gutzman's claim that, " the District of Columbia, insofar as it behaves as a state, is properly treated as a pseudo-state by the Supreme Court."
Thus, if D.C. must be treated like a state, then the federal Supreme Court can't overturn a gun ban on Second Amendment grounds, since, as noted, the Amendment (and the entire Bill of Rights) is only supposed to apply to the federal government. QED.
The Cato Institute's Tom Palmer called this line of reasoning "just plain dumb," but, anyway, that's the argument. It's the reason why not everyone is celebrating in Lincoln-hating land today. Stephan Kinsella and others are worried that the 2nd Amendment will be applied against the states through the 14th Amendment, and that highly restrictive state gun laws in places like Chicago will be struck down next.
Let me put that point more concisely: some of Ron Paul's supporters are dismayed by today's Supreme Court decision because they think it might be used in the future to prevent a democratic mob from trampling on an individual's rights. But Ron Paul himself thinks it's just fine for such mobs to restrict a person's liberty, just so long as the mob and the individual reside in the same state.
And people wonder why I refuse to call them libertarians.
Cross-posted at the Western Standard's Shotgun blog.