FROM CNN's Jack Cafferty: Teacher tenure, the union-backed safety net that protects teachers from being fired after a certain number of years of service, is coming under fire in states from New York to Tennessee and Illinois. [cnn-photo-caption image=http://i2.cdn.turner.com/cnn/2011/images/05/18/art.teacher.jpg caption=""] Tenure provides experienced teachers job security in a tight labor market, at a time when … Continue reading Should tenure for teachers be done away with?