WASHINGTON, DC – DECEMBER 6: U.S. President Barack Obama kisses performer Mariah Carey after she sang at the 91st national Christmas tree lighting ceremony on the Ellipse south of the White House December 6, 2013 in Washington, DC. The lighting of the tree is an annual tradition attended by the president and the first family. President Calvin Coolidge lit the first national Christmas tree, a 48-foot Balsam fir, in 1923. (Photo by Jim Lo Scalzo-Pool/Getty Images)