Marsha Blackburn U.S. Senator from Tennessee since 2019, U.S. Representative from Tennessee 2003-2019[86] John Bolton U.S. Ambassador to the United Nations 2005–06[87] Bob Corker U.S. Senator from Tennessee 2007-2019[88] Mitch Daniels Governor of Indiana 2005–13[89][90][91] Bob Ehrlich Governor of Maryland 2003–07[92] Newt Gingrich Speaker of the House of Representatives 1995–99; presidential candidate in 2012[93] Jon Huntsman, Jr.