Lawrence: Trump lies about Vietnam War dead in a desperate attempt to justify troops killed in Iran

Tonight on The Last Word: Donald Trump backs down from attacking Iran for the third day. Also, Trump says he could “take over” Iran if he wanted to. Plus, Republicans eye a fast track for Jay Clayton’s confirmation as Director of National Intelligence. And Josh Turek wins the Democratic nomination for Senate in Iowa. Sen. Peter Welch, Lt. Gen. Mark Hertling, Sen. Chris Coons, and Iowa State Rep. Josh Turek join Lawrence O’Donnell.