>Curtailing that freedom should be a measure of last resort.

This just feels like it turns into a cudgel against whatever groups you hate. Bad police unions? Boo! Let's ban them! Bad teacher unions? Free association is protected by the constitution so they get a pass. Catholic priests? On one hand they're consistently hated on by progressives, but on the other hand much of the arguments that can be used to defend them can be applied to teachers.