There was a lot of pre-debate chatter about a coming fight between Senators Bernie Sanders and Elizabeth Warren over Warren's assertion Sanders told her in 2018 that a woman couldn't be elected president. Sanders denied it, Warren didn't press it and a substantive debate on a range of issues ensued. Still, after the debate, it appeared that Warren declined to shake Sanders' hand. Tuesday's Democratic presidential debate in Des Moines was the final forum before the Iowa caucuses. During the debate, there was a brief skirmish between Sanders and former Vice President Joe Biden over the Iraq war.