Educational outcome is mainly due to income of parents, nothing else even comes close to matter as much.

The union seeks out what the membership wants. Teachers want seniority to be protected and rewarded, so that's what they fight for.

What force prevents unions bosses from becoming corrupt and self serving; just like we can agree a corporate boss can become? It's silly to pretend they just "always work"

Who is pretending they always work? Does something have to be perfect in order to be worth pursuing?

You state that "the union seeks out what the membership wants" and I note ( to no argument) that this surely only happens sometimes. Other times they seek other things; perhaps not to the benefit of their workers.

I'm not sure all teachers like the fact that seniority is king, and I'm also not sure that it is in fact a Net Benefit to teachers as a whole.

This doesn't make unions not worth pursuing; it just means that we should be appropriately skeptical and not make blanket statements about how they surely operate.

> I'm not sure all teachers like the fact that seniority is king

Unions don't require unanimity.

> not make blanket statements

Do I really need to add modifiers to everything I say to indicate that I'm not speaking in absolutes?

>Do I really need to add modifiers to everything I say to indicate that I'm not speaking in absolutes?

Fair and I do try not to do this wantonly. Here I feel that your gp argument breaks down in the absence of such an absolute. If indeed, we cannot prima facie trust that unions work in their members ( and their students') best interest; why shouldn't we use the troubles of unionized education ( or unionized policing...) as a caution against a possible bad outcome?

Perhaps I misunderstood; and this has just been another internet argument for the wind .