On Thursday, the Wall Street Journal’s Laura Meckler and Colleen McCain Nelson broke the news that Hillary Clinton is vetting Elizabeth Warren for the vice presidency — but not vetting Bernie Sanders. In the process, they provided a shortlist of candidates that Clinton is considering: Beyond the Massachusetts senator, other prospective candidates include Labor Secretary Tom Perez; Housing and Urban Development Secretary Julián Castro; Sens. Tim Kaine of Virginia, Sherrod Brown of Ohio and Cory Booker of New Jersey; Los Angeles Mayor Eric Garcetti, and Reps. Xavier Becerra of California and Tim Ryan of Ohio, several Democrats said. Now, this...