Well, when Palin says it is time for her followers to "reload" and prints a map with crosshairs on a political district - it obviously is enough to cause a mentally unbalanced person to actually do it.

As for Switzerland requiring rifles in homes - that is in regard to their National Guard (well-regulated militia). Our Constitution has the 2nd Amendment for that purpose and not for everyone to own handguns. The drafters of the Constitution had no idea of how technology would advance, of course, and had no idea of a semi-automatic handgun with an extended magazine. Their weapon was a single-shot musket.

As for the light-hearted comment from Archie Bunker about stabbings vs shootings - how many political killings have been made with a knife? Last I heard was Julius Caesar. If the mentally deranged person in Tucson had a knife instead of a gun, I really doubt if 6 people would have been killed.