It's dumb for all sorts of reasons and those reasons are being unpacked right now all over the Internet. I'd like add one more reason to the pile...
When I was in high school—a sophomore at St. Gregory the Great in Chicago—some kids in my class stole a teacher's car. Okay, okay: I was one of those kids. (Some of the shit I did in high school would land my on a terrorist watch list today*.) So on that day at St. Greg's, one of us (me) reached into our teacher's purse when she was distracted—I believe she was teaching at the time—and swiped her car keys. We skipped our next class, went down to the teacher's parking lot, and stole her car. We didn't keep her car—we drove it a few blocks away, parked it on a side street, and walked back to school. (One of my friends did the driving, as I didn't know how to drive then and still don't.)
Now imagine the kind of student capable of, I don't know, stealing a teacher's car or setting off explosives in his locker. Or both. Would we want a kid like that to reach into a teacher's purse and pull out a gun?
At every high school I went to—and I went to three—students regularly, er, rifled through their teachers desks and filing cabinets and purses. Now armed teachers aren't going to be able to stop a mass shooting already in progress if they don't have their guns handy. So their guns are gonna need to be in their purses, in their desks, and in their filing cabinets. Loaded and within reach at all times. Again, giving guns to every teacher in the United States for the purpose of taking out an active shooter will only work if their weapons can be accessed in an instant. And let's not kid ourselves: even if arming teachers works the way Cadet Bone Spurs and the NRA would like us all to believe—a teacher confronts a gunman with an AR15 who has already killed a half a dozen students and a teacher in another classroom who wasn't psychic and therefore didn't know to shoot the gunman before the gunman shot her first—the armed teacher from the next classroom over is only gonna get one shot. And if the gunman is a better shot than the teacher... or if the gunman is carrying a weapon that sprays a room with bullets that do this kind of damage... the armed teacher is most likely gonna wind up just as dead as the unarmed and/or armed-but-not-psychic teacher.
Once more for emphasis: teachers' guns aren't just going to be within reach of the teachers—they're going to be within reach of students too. Kids who wanna to shoot up their schools won't have to get their own guns and sneak them past metal detectors. They can just grab a teachers' gun. Again, it'll defeat the stated/alleged/bullshit purpose** of arming teachers if teachers have to keep their guns locked up in safes. And since the NRA opposes smart guns, no teacher is going to have a gun that only they can fire. So arming teachers is going to mean more shootings and more gun deaths in our schools. Which is what the NRA wants***.
A problem with arming teachers: Teacher shows up to school for work, gets out of the car with his gun. Teacher is named Philando, Tamir, or something like that. A "Good Samaritan" passerby sees the gun, calls cops. SWAT Team arrives, kills teacher. (Epilogue: NRA says nothing.)
— Robby Soave (@robbysoave) February 22, 2018
UPDATE: What he said:
I worked at Dulles airport for 7 years. On more than one occasion federal officers forgot service weapons in bathrooms. Do you think a teacher will be more aware than a trained LEO? The guns will be lost. Mishandled and accidentally fired— What Can Red Do For You? (@kerstetterjohn) February 22, 2018
* I desperately wanted to leave the school I went to before St. Greg's. I was part way through my sophomore year, though, and my parents told me I had to finish the year. So I "borrowed" a few M-80s from a friend of one of my brothers, took them to school, put them in my locker, lit the fuses, and walked away. I bombed my school. For that I got expelled, which is what I wanted, but I wasn't arrested or prosecuted.
** The real purpose of arming teachers isn't to make schools safe. It won't make schools safe. This is about selling more guns. More guns means more gun deaths, more gun deaths means more gun sales, more gun sales means more gun deaths, etc. Dead students, filmgoers, music fans, nightclubbers, office workers,
etc., are good for the gun business and the gun lobby—the NRA—will do anything in its power to up the body count, including arming teachers.
*** Fuck the NRA.