Mike Petrelli in the New York Times:

Tenure reform is no education game-changer. Tenure is just one part of a dysfunctional approach to human resource management in U.S. schools that needs a complete overhaul. Our public education system is among the only institutions in the land still pretending that professionals will spend their whole careers in a single job. The teacher compensation structure heavily favors lifers, what with its mix of low pay with generous, back-loaded retirement benefits. This is an unattractive package for millennials, few of whom picture staying in any position for more than five or ten years. 

In fact, these pensions are an important hidden factor in the tenure debate. It’s one thing for a teacher to lose her job; it’s quite another thing for her to lose hundreds of thousands of dollars of pension wealth. Because of the way pension systems are designed, that’s exactly what can happen to a burned-out veteran who is just a few years from retirement. Thus their passion for the protection that tenure provides.