The next 24 hours will be crucial for Chris Christie, top Republicans say. The New Jersey governor, who was on top of the political world two months ago as he cruised to reelection over his Democratic challenger now finds his status as the potential front-runner of the 2016 GOP presidential field imperiled. The test comes with the release of e-mails and text messages that tie top members of his administration to the closure of two lanes leading to a crucial bridge in what appears to be political retaliation against a Democratic mayor who refused to endorse Christie’s reelection. Republican communications...