New Jersey Gov. Chris Christie scored a big win for his agenda in June when he persuaded the state legislature to pass a public employee pension and benefits overhaul. The bill, which the governor’s office said would save New Jersey taxpayers $120 billion over 30 years, was the product of a yearlong negotiation between Christie and the Democratic leaders of the state senate and assembly, though it did not receive the backing of most Democrats in either chamber. Those that did support the bill are now paying a political price, with the state’s most powerful union, the New Jersey Education...