There is an excellent article over on the Washington Monthly site that is definitely worth a look, The Second Amendment Is an Anachronism by Martin Longman. In it, Longman takes a good hard look at the second amendment, where it came from, and why it is really in the Constitution.
His answer? It was written into the basic law of the land because the Founders feared a central government with a standing army. It seemed, to them, a more or less overt invitation to tyranny. So, instead, they planned for a group of state militias (“a well regulated militia”) that would come into being, or unite as a standing army, when necessary, and then fade away when it wasn’t needed.
The problem, as even the Founders themselves soon discovered, was that the solution was frankly unworkable. Dangerous as they may be, standing armies and navies are necessary if you want to have a country that can defend itself against aggression.
As a result, he says, the 2nd Amendment was obsolete almost from the second it was written. Today, it is a hazardous holdover, like a vestigial organ which plays no role in the functioning of the body, but which can all too easily become infected and dangerous.
The only answer, he says, is to remove the 2nd Amendment from the Constitution before it can cause any more harm—sort of the way that a diseased appendix must be removed before it can burst and cause the death of its owner.
The Little Professor