Democratic candidates in final debate before Iowa caucuses
Presidential candidates field questions at the Democratic primary debate in Des Moines, Iowa
From left, Democratic presidential hopefuls billionaire-philanthropist Tom Steyer, Massachusetts Sen. Elizabeth Warren, former Vice President Joe Biden, Vermont Sen. Bernie Sanders, Mayor of South Bend, Ind., Pete Buttigieg and Minnesota Sen. Amy Klobuchar on stage ahead of the seventh Democratic primary debate. (Kerem Yucel/AFP via Getty Images)