When Obama makes his last gasp totalitarian grab, he will first take every military base in America with his Secret Police Forces (DHS police, etc.). He cannot trust loyal Americans in the military and their bases are setup to be easily overrun. Just take over the base armories by executive order. IMHO.
20 years ago that might have worked, now there are millions of AR-15, AK-47, SKS and Mosin Nagants out there in public hands. Also, those same people who bought them also bought a crap load of cheap surplus ammo to go with them.