Two Senate committee chairmen authored a letter to a former Hillary Clinton aide pushing him to accept limited immunity in order to testify before Congress on the set-up of the former secretary of state’s private server.First reported by McClatchy, Sen. Chuck Grassley (R., Iowa), chairman of the Senate Judiciary Committee, and Sen. Ron Johnson (R., Wis.), who chairs the Senate Homeland Security Committee, sent the letter to ex-State Department computer staffer Brian Pagliano and his lawyer Friday emphasizing the possibility of an “immunity order.”In response to a subpoena from the House Select Committee on Benghazi, Pagliano’s attorney Mark MacDougall told...