I assume the assailant was part of a "well-regulated militia," which is a key concern of the 2nd Amendment folks. You know, if all those kids had guns in their backpacks, fewer of them would have been shot. Hey, look, I'm a dumbshit!
After of a few decades of gun manufacturers' propaganda funneled through the once-honorable NRA, it is too late for any politician to propose enforcing the original intent of the 2nd Amendment with a program of universal militia training, after which the successful graduates would be free to purchase and possess any firearm they wished.