Antonin Scalia's Second Amendment:
Even so, the D.C. ordinance was too broad a restriction.
A well-regulated Militia, being necessary to the security of a free State,the right of the people to keep and bear Arms, shall not be infringed.
My view: The Second Amendment's purpose is to vest in the people enough power to forestall both invasion and coup d'etat. For that purpose, the people individually and collectively have the right to arm themselves, but the regulation clause allows reasonable restrictions consistent with the purpose.
This means there's no bright line, and we'll have to continue to argue about it for a long time. If I want an RPG launcher to defend myself against the (mythical) black helicopters, well, that's still illegal, though I hear they're readily available in Baghdad.
What's to be done to keep people from killing each other? Handgun - or all firearm - registration would be consistent with my interpretation. That would drive the gun nuts crazy, especially if Obama wins, and for sheer entertainment value, I would recommend it as a next step in D.C. (Of course, since Congress has final Constitutional authority over D.C.'s laws, if local officials passed this, they'd probably get their 35-year-old home rule revoked in a hurry.)
It'll be interesting to see what happens to gun crime rates this summer and fall. And, when I say 'interesting', I mean from a safe distance. But it is clear that the ban hasn't been, ahem, 100% effective up to now. The question is whether we'll find out that it used to be 50% effective.