It seems like this is what every liberty-leaning state should do. Forget all the other issues for now. Just argue the fiscal savings of the state not spending administrative costs on, what amounts to, doing the union's work for them.
There's no doubt in my mind that every single union would be kaput in less than 5 years time. Maybe 2 or 3, even.
Also there should be alternatives to union group premiums for professional insurance. A teacher told me years ago that the ONLY reason he belongs to the union is because of the insurance. If he carried solo, it would be more than his union dues and the insurance premiums through the union combined.
The states should figure out a way to make those insurance rates affordable to teachers. Then it’s absolutely bye bye to the unions. They’ll be left only with teachers whose courses are easily dispensable. I’ve noticed locally that the teachers most engaged with the unions (union reps) are PE teachers, not usually classroom teachers.