The unions have an obligation to a safe and sane environment for the work their members do. This is a work place issue and the standards administrations are using are not enough to ensure the safe practice of teaching.
Violence in the work place is a huge problem and there is every reason to believe it is making a come back. For awhile a few years ago work place violence was frequent, then it settled down, but, I think it is going to become more common place.
The permission Trump gave to people to commit violence in the name of their country within it's borders is a real problem, not simply a make believe problem. It is real and people are highly aggitated. It is time for unions to again address safe work environments.
Unions can set their own standards and then expect the employer to comply to be sure violence is put in check.
