Some of the material in this post was adapted from an article by Karen E. Magee in the timesunion.com newspaper.
Most people outside of the education world are very confused about tenure. They think it means that a teacher cannot be fired. This is NOT what tenure means nor was tenure put in place for this purpose. Tenure entitles teachers to due process to a fair hearing before an impartial third party if a district seeks to discipline or fire a teacher. This is the same protection given to police officers, firefighters, and other public servants. It prevents teachers from being dismissed as a result of an arbitrary or capricious whim.
In most districts, everyone, except employees hired under civil service and the superintendent, is eligible for tenure. In New York State teachers and administrators earn tenure after a three-year probationary period. In public education, teachers, administrators, and other school staff must be free to speak out on important issues without fear of reprisal. Teachers and administrators must be able to advocate for their students without fearing they can be arbitrarily dismissed for doing so.
Picture what would happen if teachers---maybe even your child's teacher---could be fired at will. Currently, teachers are voicing their opinions about excessive standardized testing. They are able to ask about budgets and budget cuts. Most importantly, in communities where rising property taxes are triggering loud opposition, they don't have to worry that their school board will simply lay off the most expensive teachers---even if they happen to be the best and most experienced---so that the district saves money.
Tenure has been loudly criticized because it has become such a burden to discipline or fire a teacher. In New York that process has been streamlined. In 2012 the law was amended to require all disciplinary hearings to be completed within five months. Most cases are settled before it gets that far.
Tenure allows teachers to teach and administrators to do their jobs. It creates an atmosphere of academic freedom--an environment in which the entire school community will thrive.