In this June 23, 2017, file photo, Sen. Dean Heller, R-Nev., is shown during a press conference at the Grant Sawyer State Office Building in Las Vegas. Rep. Jacky Rosen, D-Nev., officially announced her candidacy Thursday, July 6, 2017, for the Senate seat currently held by Heller. (Erik Verduzco/Las Vegas Review-Journal via AP, File)