Barack Obama, U.S. senator from Illinois and Democratic pres

UNITED STATES - JUNE 26: Barack Obama, U.S. senator from Illinois and Democratic presidential candidate, walks to his seat at a table following his opening remarks during an Economic Competitiveness Summit at Carnegie Mellon University in Pittsburgh, Pennsylvania, U.S., on Thursday, June 26, 2008. Rick Wagoner, chief executive officer of General Motors Corp. and John Surma, chief executive officer of U.S. Steel Corp. are among the executives speaking at the summit. (Photo by Daniel Acker/Bloomberg via Getty Images)