Democratic presidential candidates Sen. Elizabeth Warren, Tom Steyer and Sen. Bernie Sanders during a heated exchange at the debate at Drake University in Des Moines. Photo: Robyn Beck/AFP via Getty Images
Sen. Elizabeth Warren appeared to reject Democratic presidential rival Sen. Bernie Sanders' handshake after the progressive pair clashed during Tuesday night's debate in Des Moines, Iowa.
Driving the news: The longtime friends were at loggerheads during the debate on the North American trade deal and whether Sanders said a woman could be elected president. Here's what else unfolded, in photos.