Eric Hanushek offers a few timely observations in this Wall Street Journal op-ed.

All sides of the educational policy debate now accept that the key determinant of school effectiveness is teachers?that effective teachers get good achievement results for all children, while ineffective teachers hurt all students, regardless of background. Also increasingly accepted is that the interests of teachers unions aren’t the same as the interests of children, or even of most teachers.

[Snip]

Teacher’s unions say they don’t want bad teachers in the classrooms, but then they assert that we can’t adequately judge teachers and they act to defend them all. Thus unions defend teachers in “rubber rooms”?where they are sent after being accused of improper behavior or found to be extraordinarily ineffective?on the grounds that due process rights require such treatment. (In a perverse way, rubber rooms are good as long as it is not feasible to remove teachers that are harming kids; it is better to pay these teachers not to teach than to have more children suffer.)

So we are seeing not a war on teachers, but a war on the blunt and detrimental policies of teachers unions. If unions continue not to represent the vast numbers of highly effective teachers, but instead to lump them in with the ineffective teachers, they will continue doing a disservice to students, to most of their own members, and to the nation.