Bill Clinton hits the campaign trail for Hillary Clinton (13 images)

Former President Bill Clinton makes remarks as he campaigns for his wife, Hillary Clinton, a 2016 Democratic presidential contender, at the Czech & Slovak Museum, January 7, 2016, in Cedar Rapids, Iowa. Hillary Clinton is running against former Maryland Gov. Martin O'Malley and Vermont Sen. Bernie Sanders ahead of Iowa's first-in-the-nation caucuses February 1. Photo by Mike Theiler/UPI

Former President Bill Clinton makes remarks as he campaigns for his wife, Hillary Clinton at the Czech & Slovak Museum, January 7, 2016, in Cedar Rapids, Iowa. Photo by Mike Theiler/UPI

Former President Bill Clinton greets supporters as Sarah Elliott makes a "selfie", as he campaigns for his wife, Hillary Clinton, at the Czech & Slovak Museum, January 7, 2016, in Cedar Rapids, Iowa. Photo by Mike Theiler/UPI

Former President Bill Clinton campaigns for his wife, Hillary Clinton at the Czech & Slovak Museum, January 7, 2016, in Cedar Rapids, Iowa. Photo by Mike Theiler/UPI