Glenn Reynolds: ...it's important to understand that to the Framers the "militia" wasn't some specialist unit of government employees, but a group consisting of the armed populace; one that, though in some ways organized by the government, was also in some ways set against the government, as a check.

The pro-control argument that the 2nd Amendment is too vague or would never have been put in place if modern weapons were available only seem valid when considered just in light of the text of the amendment itself. When one reads the supporting documents from the people who framed the Constitution, it's quite easy to see they did in fact mean the populace should be able to arm itself without interference from the government. While there were no machine guns back then, large caliber weaponry was still quite common, and yet there is no, "except for big shotguns and cannon" in the amendment. In fact, from what I've read, the framers of the Constitution most likely would've explicitly included our right to own Howitzers and .50 caliber machine guns, if they'd known such things could exist and that the citizens of their country would be able to buy them one day.