FILE - In this April 2, 2014, file photo, Sen. Dean Heller, R-Nev., questions General Motors CEO Mary Barra on Capitol Hill in Washington before the Senate Commerce, Science and Transportation Subcommittee. Rep. Jacky Rosen, D-Nev., officially announced her candidacy Thursday, July 6, 2017, for the Senate seat currently held by Heller. (AP Photo/Pablo Martinez Monsivais, File)