In more of their trademarked absurdity impersonating serious, adult public policy-making the NRA said that the cure for gun violence is (BIG SURPRISE!) an a$$load more guards in schools. They think that hundreds of thousands of schools now need to have round the clock armed guards. Pre-schools, elementary schools, middle schools, high schools, trades schools, barber colleges, etc. But we can't stop there. What about theaters. We need armed guards there. And what about restaurants. People get shot at McDonalds, and Denny's too, so I guess they need full-time armed guards. Then there's churches. They will need a bunch of armed guards patrolling the pews. And what about supermarkets. They usually just have a few burly high school students who played football, but now they will need to be slinging assault rifles. How about libraries? How about gyms? There's really no end to where people will need armed guards carrying automatic rifles to protect them. All from the terror that the NRA unleashed on them in the first place by making guns too easy for irresponsible people to get their hands on in the first place. And they did it for the money that comes from the gun manufacturers, and the money from the irresponsible people who want guns kept easy to get, and the power that comes with leading an unofficial army of authoritarian dip$hits.
This is the protection racket treadmill that the NRA has devised. Create the threat in the first place and then justify more armament to protect you from the first bunch. Then you need protection from the second bunch and the third bunch, ad infinitum.
The general problem is their philosophy. Even if 99% of people carrying weapons are sane and responsible (which if much higher that in reality) it only takes 1% or so to totally destablize things. Remember that many of these people are already SUICIDAL. Therefore the fact that they might get shot during their rampages is an unlikely deterrent. They can easily kill a few dozen people who are caught off guard before they are stopped.
Philosophically, the problem is that the more people who you entrust with guns the more likely you are to get unlucky and have those guns and that security duty entrusted to someone who is a psychopath. It's no secret that psychopaths are attracted to things like guns because it gives them the instant, unearned authority and power that they crave. Why would a bully not be attracted to a gun? It's a great way to bully and intimidate others who are less aggressive than they are.
Adam Lanza's killing spree only took minutes. Even there had been an armed guard, there is a good chance that he wouldn't have responded until it was too late. Cops are already armed, but they can't be everywhere at once. Most of the time they are responding after the fact, when all they can do is mop up the mess.
The NRA's crazy solution is to do more of the same and to make the mess even bigger.