Lawrence: Trump failed to explain his war, disgraced military calling it 'a little journey to Iran'

Tonight on The Last Word: Donald Trump refers to the deadly war as “that little journey to Iran.” Also, the Supreme Court justices push back on the Trump birthright citizenship case. And a federal judge orders the University of Pennsylvania to provide a list of Jewish employees. Rep. Jason Crow and Professor Laurence Tribe join Lawrence O’Donnell.