According to the second amendment, the right to bear arms shall not be infringed as to keep the people of the United States prepared for any possible tyranny from the state. That being said, it would therefore be deemed logical that anything that the U.S. Army is allowed to have, should therefore be allowed to be owned by the citizen. This is (one of the reasons) why assault rifles are allowed, and this is therefore why anything, from a compact pistol, to a 1 Mt nuclear warhead is therefore a Constitutional right.
The popular assertion of the gun fetishists is that the right of the people to keep and bear arms shall not be infringed (the militia clause notwithstanding). This has lead many of the more avid "enthusiasts" to advocate for the legal civilian ownership of any weapon under the sun, including high explosives, chemical ordinance, fissile material, and deadly biological agents. To any rational observer, this desire for WMDs in the hands of civilians is psychotic on the part of these so called "enthusiasts"
It's bad enough that terrorists, rogue nations and similar degenerate organisations and individuals can get hold of such powerful tools. There is a huge difference between one of those and your typical handgun or shotgun used for hunting, self-defence etc. Owning a gun for self-defence is sensible, but what use would a private individual have for a nuclear warhead?! Anyone who wants to own such a thing is either completely off their rocker, or they're planning some form of really nasty terrorist type stuff, so a big, fat, NO!