Chris Christie is plunging into what amounts to a cross-country revival tour, looking to recover from a clumsy political scandal and reclaim his place as a promising Republican presidential prospect. In one recent week, it was on-the-ground politics in Tennessee and New Mexico. This week, after a campaign stop in Pennsylvania, the New Jersey governor returns to the late night comedy circuit with an appearance on NBC's "Tonight Show." Then he'll stop by Mitt Romney's Utah summit, a private event for donors and GOP establishment leaders, and the week after that he heads to Washington to court Christian conservatives at...