Gov. Chris Christie’s tough-on-schools approach in a state that has zealously protected its public schools–and its teachers–has already put him at loggerheads with legislative leaders, unions and some parents in New Jersey, reports the New York Times. And on Tuesday, the governor, a Republican, used his State of the State address to push his education agenda further by calling for an end to teacher tenure, on top of his support for merit pay for teachers based partly on student achievement and adoption of a voucher-like system that would give students in low-performing schools other options…