WASHINGTON — Pledging to empower America's "forgotten men and women," Donald Trump was sworn in as the 45th president of the United States Friday, taking command of a deeply divided nation and ushering in an unpredictable era in Washington. His victory gives Republicans control of the White House for the first time in eight years. Looking out over the crowd sprawled across the National Mall, Trump painted a bleak picture of the nation he now leads, lamenting "American carnage," shuttered factories and depleted U.S. leadership.