What happens if a state with a population roughly equal to that of Kentucky and Louisiana combined held a major election and no one noticed? That seems to be occurring in New Jersey, which is electing a new governor this year. It may be the Democrats’ biggest gubernatorial win in the state in over 40 years. A Democratic romp in a state Hillary Clinton won easily might not seem like a surprising result. But New Jersey usually features competitive governor’s races. Over the past 40 years, Democrats have won the governor’s mansion four times to Republicans’ six. New Jersey’s current...