The death, at age 89, of Democratic senator Frank Lautenberg has put a wrinkle in the reelection plans of New Jersey governor Chris Christie. The cantankerous Republican enjoys high approval ratings and a chasmic lead over Barbara Buono, a Democratic rival so weak that former governor Brendan Byrne, now the Garden State’s Democratic elder statesman, has hinted she should think about dropping out. But the need to appoint an interim replacement for Lautenberg, and to schedule a special election to fill out his term through 2014, has created a pair of new challenges. First, does Christie hold the special election...