Chris Christie needed a win. On Thursday night, he got one. Christie, the New Jersey Republican challenging incumbent Democratic governor Jon Corzine, has seemed aimless in recent weeks, fading in the polls just as this tight gubernatorial race enters its final stretch. In early August, a Monmouth/Gannett poll showed Christie ahead by 14 points; this week, the same poll showed him ahead by just three. Wednesday’s Quinnipiac poll also showed Christie only slightly ahead, 43 percent to 39 percent. In July, Quinnipiac had Christie besting Corzine by 13 points. The catalog of reasons for Christie’s drop is as long as...