LAS VEGAS, NV - FEBRUARY 20: Democratic presidential candidate former Secretary of State Hillary Clinton and her husband former U.S. president Bill Clinton greet supporters during a caucus day event at Caesers Palace on February 20, 2016 in Las Vegas, Nevada. Hillary Clinton defeated Democratic rival U.S.Sen Bernie Sanders in the Nevada Democratic caucuses. (Photo by Justin Sullivan/Getty Images)

LAS VEGAS, NV - FEBRUARY 20:  Democratic presidential candidate former Secretary of State Hillary Clinton and her husband former U.S. president Bill Clinton greet supporters during a caucus day event at Caesers Palace on February 20, 2016 in Las Vegas, Nevada. Hillary Clinton defeated Democratic rival U.S.Sen Bernie Sanders in the Nevada Democratic caucuses.  (Photo by Justin Sullivan/Getty Images)