When Mississippi Sen. Thad Cochran filed papers to run for another term, the snowy-haired Republican listed the address of his campaign as a P.O. box in Tupelo, a town best known as the birthplace of Elvis Presley and a hub of the state’s conservative, northeast corner.

Thad Cochran’s political resurrection began with a campaign shakeup and ended with a Hail Mary television ad. Just three weeks ago, in the dead of night on June 3, the Mississippi senator’s staff sat shaken and dejected, crestfallen at the results of a primary that deprived the six-term incumbent of an