In late 2020, Sen. Robert Menendez (D-N.J.) met with Philip Sellinger, a private practice lawyer and former fundraiser for the senator, to assess his potential fit as the next U.S. attorney for the state of New Jersey - and to discuss one case in particular. If appointed, Sellinger would assume control of one of the largest prosecutor’s offices in the country, a post that comes with the power to bust mob bosses and go after corrupt public officials. But Menendez, federal prosecutors say, was fixated on a less consequential matter: ensuring the future prosecutor would act sympathetically toward a friend...