Presidential hopeful Hillary Clinton gestures while standing beside Bernie Sanders during a photo spray of the candidates during the first Democratic presidential debate in Las Vegas, Nevada on October 13, 2015. Democratic presidential frontrunner Hillary Clinton will finally square off with top rival Bernie Sanders in the party’s first debate of the 2016 campaign as she seeks to prove she is the candidate to beat.AFP PHOTO / FREDERIC J. BROWN FREDERIC J. BROWN/AFP/Getty Images FILE – In this Sept.