Mitch McConnell(L), new leader of U.S. Senate's majority attends the swearing-in ceremony at Capitol Hill in Washington D.C., capital of the United States, Jan. 6, 2015. On Tuesday, Mitch McConnell, a 72-year old senator from Kentucky, became the U.S. Senate's majority leader, following Boehner to be one of the two most powerful Republicans in the nation. (Xinhua/Bao Dandan)