Candidates clash at the 7th GOP debate in Des Moines, Iowa.<br />more at cnn.com.<br />Republicans Face Off In First GOP Debate Of 2016 Election GOP Debate, Gop Debate 2016, Gop Debate Live Updates, Gop Debate Live Video, Republican .<br />Donald Trump tries to take a serious tone while rivals Sen. Marco Rubio and Sen. Ted Cruz spar over immigration reform. CNNs Dana Bash reports.
