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, smiles as he greets attendees of an an Economic Competitiveness Summit at Carnegie Mellon University in Pittsburgh, Pennsylvania, U.S., on Thursday, June 26, 2008. Obama told a gathering of research and business leaders, including General Motors Corp. Chief Executive Officer Richard Wagoner, that he would invest government resources in education, energy, health care and science to revive the U.S. economy. (Photo by Daniel Acker/Bloomberg via Getty Images)