WASHINGTON — Pope Francis arrived Tuesday on the first visit of his life to the United States, bringing his humble manner and his "church of the poor" to a rich and powerful nation polarized over economic inequality, immigration and equal justice. According a rare honor to the pontiff, President Barack Obama and his wife and daughters met Francis at the bottom of the stairs on the red-carpeted tarmac at Andrews Air Force Base in Maryland after the pope's chartered plane touched down from Cuba. Presidents usually make important visitors come to them at the White House.