Sen. Barack Obama (D-IL) pauses as he delivers a speech on race and politics at the National Constitution Center in Philadelphia, Pa. on Tuesday.
Sen. Barack Obama (D-IL) pauses as he delivers a speech on race and politics at the National Constitution Center in Philadelphia, Pa. on Tuesday. Tom Gralish / Philadelphia Inquirer / MCT
Sen. Barack Obama (D-IL) pauses as he delivers a speech on race and politics at the National Constitution Center in Philadelphia, Pa. on Tuesday. Tom Gralish / Philadelphia Inquirer / MCT