How important is teacher tenure in our education system?

Teacher tenure is basically a permanent contract with teachers, “ensuring them a guarantee of employment for life”.  The practice began in the early 20th century when changes in political parties, racial or personal bias could result in an otherwise excellent teacher being fired.   Now the practice makes it nearly impossible to fire bad teachers. I feel that most employers should have to show “just cause” for firing an employee.   In the teaching profession, the dismissal review process can be very involved and costly.  “Some states and school districts are beginning to turn to merit-based models for tenure and pay.”  The Center for Education Reform, President Jeanne Allen said,  “Many states have set the bar too low for the achievement of tenure”.    With the huge amount of influence that teachers have in the lives and development of self-esteem in our kids, it’s not fair to waste our children’s time and growth in school years trying to weed out the most ineffective educators.  Our kids deserve the best educational opportunities available, and to be surrounded by those best-suited to bring out their full potential.  More than in any other profession, those who are burnt-out or tired of the young minds in need of constant inspiration, they should retire and allow fresher, more innovative instructors to take over, revamping the tired, old system into a new paradigm of learning.