The 2nd Amendment is fine. It is just as dangerous as the 3rd Amendment (No soldier shall, in time of peace, be
quartered in any house without the
consent of the owner, nor in time of war
but in a
manner to be
prescribed by law). It is also just as relevant to this whole debate. They both are anachronistic and should be generally ignored.
The 2A exists because after the Revolution, the new nation needed a way to defend itself. It did not have a standing army. We used militias instead. The only way that works is if each Militia member had a gun to bring when called up. That context actually makes the entire text of the 2A make a little more sense:
"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."
The 2A does NOT say that anyone who wants to own a gun can own one. It says you have the right to own a gun for the purpose of serving in your militia.
Since we have a standing army, we no longer generally need militias. The US still has one though just in case. Its called the Selective Service (the draft). If the security of the free state was at risk and the standing army could not suffice, the draft would be instituted and millions of young men would be called up to fight, just like they were in a militia....with ONE BIG EXCEPTION. They wouldn't need to bring their own gun...