Per the assault rifle discussion I have two points to make:
First is the distinction between "assault rifle" which is a very specific term, used to designate a hand-held weapon, capable of firing full automatic, that fires a cartridge halfway between that of a pistol (full-auto weapons firing pistol cartridges are called sub-machine guns) and that of a full rifle (firing a full rifle cartridge designates a weapon as a machine gun). The term "Assault weapon is a term used only for legislative purposes that has no concrete definition, and every location with an assault weapon ban has different classifications, so that anything from a Marlin .22LR small game rifle (classified as an assault weapon in New Jersey at one time because it has semi-automatic fire and can hold more than 15 rounds in the integral magazine) to semi-automatic versions of military equipment.
The second is that a great many Americans believe that a governemnt with nothing to fear from it's citizens lacks an integral check on it's power, thus the mere threat of an armed citizenry provides a sufficient impetus to keep the government in line. Not all of these persons hoard weapons to overthrow the government, many do not even own one, because they feel that, as long as the population as a whole is armed, there will never be a need to go beyond the ballot box.