A rather important qualification

which is not extended far enough.

while I understand that teachers also lobby for things that are good for kids, like better supplies, this does not make powerful teacher's unions a good idea. Teacher's lobby for kids when it happens to coincide with their interest. Unfortunately, in urban areas, it often doesn't.

I should probably clarify that I'm talking about twenty, maybe thirty failing urban school districts/agglomerations in the United States. I could care less whether Scarsdale has a powerful teacher's union that negotiates triannual ten month paid leave in Hawaii. And the problem in rural areas is not the teacher's unions, it's the geographic fact of no possible competition, and often the net outmigration of educated people who might make good teachers. [my emphasis]

Nevermind the teachers' unions, because of those 20 or 30 districts we should dismantle the entire national school system and start over from scratch with an ideologically driven unproven method that in no way is obviously designed to be gamed into segregation of students by economic class and/or race.
This is rather like the justification for the logging now going on in our national forests; there's a few old, dying trees in those acres, so they need to be clear cut for their own health.
I don't get it. Aristotle was arguably a conservative (arguably), yet they all suck at logic.