"How can I say this politely?

The Constitution does allow the government to conclude that there are certain types of weapons that no one can legally known. Now, if that were not the case, then you should be able to go buy a flame-thrower that the military has. You should be able to go, if you're a billionaire, buy an F-15 loaded with ordnance. You should be able to buy an M1 tank. You should be able to buy a machine gun. You should be able to buy a grenade launcher. And you can't do those things."

~~~

How can I say this politely, Vice President Shithead?

You're a fucking moron:

Grenade launchers
http://www.autoweapons.com/products/destructivedevices.html

Machine guns
http://www.autoweapons.com/products/products.html

Flamethrowers
http://flamethrowerexpert.com/broke.html

http://die-less.com/2012/01/13/flamethrowers-getcher-flamethrowers-here/

Tanks
http://www.site.ww2mv.com/M18_Hellcat_For_Sale.php

Aircraft
http://www.globalplanesearch.com/warbirds/combat/ 

Now, please cite the part where "The Constitution does allow the government to conclude that there are certain types of weapons that no one can legally known."

BTW, flamethrowers are unregulated by federal law, and the military doesn't use them anymore.