"Teacher security" is the primarly problem. We have both young and old teachers who have gained tenure status and are no longer interested in their own professional development or the entire improvement of a school system. They just want to close the door, "teach" and not be held accountable. They refuse to use research based instructional techniques or even develop common grading or behavioral expecations as their peers. I (as a teacher) have sat back and watched teachers be placed on "growth plans" by the principal, they go through the needed steps for one year and then revert back to their old habits of being inaffective and poor. The principal is left pulling his/her hair out because when it is all said and done, there is nothing they can do. The cost of removing a tenured teacher is so expensive that district simply can't afford it. The funny thing is, most teachers are outstanding, the union is actually weakening itself in the court of public opinion, by protecting the ineffective / poor teachers within its ranks. Tenure reform is badly needed!