Donald Trump denigrated his former defense secretary, James Mattis, as the 'world's most overrated general' after the military veteran published a scalding op-ed denouncing the president's leadership in the face of widespread protests across the country. Mattis spoke out for the first time publicly since his acrimonious December 2018 exit from the White House by blasting Trump as making a 'mockery of the Constitution' in a fiery statement shared Wednesday ...