In his remarkable run for the White House, billionaire real estate developer Donald J. Trump presented himself as the ultimate political outsider to leapfrog 16 Republican primary opponents and went on to best the well-organized, well-financed campaign of Democrat Hillary Clinton. Mr. Trump is now poised to become the 45th president of the United States, and because Republicans have retained control of both the Senate and the House of Representatives, they will therefore control both political branches in Washington, DC.