Mitt Romney
U.S. senator from Utah, former Massachusetts governor
Rob Portman
US Senator from Ohio (2011-present); former US Representative (1993-2007); former dir. OMB
Republican National Committee
U.S. political committee that leads the Republican Party of the U.S., a/k/a The Grand Ol' Party/GOP
National Republican Senatorial Committee
Campaign committee for Republican U.S. Senate candidates
Roy Blunt
US Senator from Missouri (2011-present); former US Representative 1997-2011
Marco Rubio
US Senator from Florida; (2011-present); 2016 GOP Presidential candidate
Kelly Ayotte
Former Republican US Senator from New Hampshire, gubernatorial candidate