Las Vegas Sands Corp. Chairman and CEO Sheldon Adelson speaks at the Global Gaming Expo 2014 at the Venetian Las Vegas on October 1, 2014 in Las Vegas, Nevada. Ahead of a Las Vegas summit gathering together Republican presidential hopefuls for meetings with mega-donor Sheldon Adelson, a new report is out about the casino magnate’s purported favorite to win 2016: Florida Sen. Marco Rubio.