A conservative legal advocacy group submitted plans Tuesday to question under oath seven current and former top State Department officials and aides to Democratic presidential contender Hillary Clinton — but not Clinton herself at this point — about her use of a private email server when she was secretary of state. Judicial Watch said its deposition plan includes Cheryl D. Mills, who was Clinton’s chief of staff at State; Huma Abedin, a top aide who served as Mills’s deputy and who now is vice chairman of Clinton’s presidential campaign; and Bryan Pagliano, a Clinton staff member during her 2008 presidential...