Don't mistake my personal choice not to carry around my AR 15 everyday with the idea that the 2nd Amendment is part of a Bill of Needs. The Constitution does not qualify the right to keep and bear arms, it simply states that the right exists and cannot be "infringed"; as much as I am troubled that certain people have firearms who, in my estimation, are not playing with a full deck, in the absence of the commission of a criminal act, they have the right to own these arms. In my 30-odd years of living in California, I have only once seen a pickup truck with an AR in the back window rifle rack in public. I have however, seen many, many of these arms at both public and private shooting ranges. It is in my estimation, the best current Homeland Defense Rifle, and its ownership should be encouraged as a matter of national defense.
If we were to cede validity to the idea that some people are too flaky to be allowed to own a gun we would also have to take a look at the mental stability of millions of people who are allowed to get behind the wheels of cars.
After all, only about 40% of all fatal auto accidents are attributed to alcohol perhaps some of the other 60% are caused by conspiracy theorists who can't take their eyes off of the rearview mirror!