As I wrote earlier, who gets to pick the teachers that'll pack heat?
Will it be some school board-designated committee (because we know how they LOVE justice)?
Will it be union goons?
Maybe it'll be the librarian who just added a bunch of Antifa books to the catalog.
Maybe it'll be these Fearless Ladies.
Or that collection of sex ed specialists pushing the latest claptrap on children.
It sure won't be the parents, who are "domestic terrorists" in the eyes of the DOJ.
I'll go a few steps further....let's say some leftist agitator-teacher who did 4 years in the Army's is deemed "competent." He sees a bunch of conservative students and monitors their online activity, decides they're a threat because they wrote "Let's Go Brandon" and FJB and posted pictures of them at gun shows on Instagram, and draws his weapon on them in class and calls the cops.
He will argue (and, I submit to you, be supported in the press and by the school board vociferously) that he stopped a possible disaster. The parents of these students will sue, the NEA will protect the teacher at all costs, the parents will spend thousands on legal fees and their kids will be doxxed and have a hard time getting in to college or trade school.
The teacher will keep his job and become a celebrity for 20% of this nation, and be loathed by 30-40% of the Deplorables. The remainder/ballast will waffle. Meanwhile, another school shooting will happen because that's part of the systematic risk in a free nation.
For a nation like Israel where the citizenry has experienced this palpably, and where the threat is probabilistically high (way higher than in America), it seems to work. I also suspect "competence" isn't as politically defined in Israel. Israel isn't America, and America isn't Israel, just like adopting the gun control policies of Europe won't work here.
In contemporary America, this is a nice idea on paper. In practice it'll fail, because the local government and DOJ will make the call on "competency." And then this guy will carry...
Viable options include Homeschooling and private schools. But as long as in loco parentis reigns supreme, this is a futile situation.