And these armed guard arguments seem to hinge on the idea that some security guard making $10 is an invincible killing machine.
Really, it's a demonstration of the hold the NRA has over some people: rather than requiring gun owners to accept any limits whatsoever to their hobby, we've got people pretending that keeping a bucket of rocks in the corner is a deterrent. That if we watch the exits like a hawk nobody's gonna sneak a gun in (find me a backpack that doesn't have some sort of CCW provision these days). That if we arm the teachers they'll somehow only shoot the right person and won't get shot in turn when the SWAT team shows up. 
Yes. That was my Facebook feed until some pruning. Some of my gun ramblings are based on living in Georgia and dealing with some very ignorant gun owners who like to argue, but I asked a guy why he needs an Ar-15. They're apparently good for shooting varmints. Bubba holds down suppressive fire on the possums while John Boy picks off the senior officers? Are ya sure you don't just like firing it?
Well, here's the thing. He's not wrong. Great thing about an AR is they don't kick worth a squat, they shoot really flat and if you miss the first time, you just go plinkplinkplinkplinkplink until the prairie dog is either underground or pink foam. In a simpler world you did this with a .22, probably even a bolt action one. But because the powder charge is a fraction of 5.56, the slug is going like half the speed despite being roughly the same caliber. And since nobody of conscience sports .22LR for "self defense" the proliferation of 5.56 has made it so you might as well take out a coyote with the same caliber you used to take out the 'cong with.
I don't even know that the guy farms. He certainly doesn't do much except heroin... I don't know what he means by varmint. Except for coyotes there's not much here that could pose a threat to livestock so I just imagined him opening up on possums. He could be just wildly firing at a field to try to hit the occasional boll weevil. I made him pause when I compared guns to tablesaws because I'm a woodworker and so is my grandpa. Some pained analogy that caught his attention because familial bonding I guess