President Barack Obama and First Lady Michelle Obama wait in a hallway at the Washington Hilton Hotel in Washington, D.C., moments before taking the stage at the White House Correspondents Association dinner, Saturday, May 1, 2010.

President Barack Obama and First Lady Michelle Obama wait in a hallway at the Washington Hilton Hotel in Washington, D.C., moments before taking the stage at the White House Correspondents Association dinner, Saturday, May 1, 2010.

President Barack Obama exits the stage with University of Michigan president Mary Sue Coleman after delivering the commencement address to University of Michigan graduates at Michigan Stadium, in Ann Arbor, Mich., Saturday, May 1, 2010.

President Barack Obama exits the stage with University of Michigan president Mary Sue Coleman after delivering the commencement address to University of Michigan graduates at Michigan Stadium, in Ann Arbor, Mich., Saturday, May 1, 2010.

President Barack Obama touches the sign above the locker room door at Michigan Stadium, before giving the commencement address to University of Michigan graduates in Ann Arbor, Mich., Saturday, May 1, 2010.

President Barack Obama touches the sign above the locker room door at Michigan Stadium, before giving the commencement address to University of Michigan graduates in Ann Arbor, Mich., Saturday, May 1, 2010.