Obama Protection 46

A Secret Service agent perspires as he keeps watch on U.S. President Barack Obama during a campaign event at Carnegie Mellon University in Pittsburgh, Pennsylvania July 6, 2012. Obama is on a two-day campaign bus tour of Ohio and Pennsylvania. Reuters

President Barack Obama greets staff and family members of the 911th Airlift Wing in Coraopolis, Pa. , Friday, July 06, 2012 after speaking at Carnegie Mellon University in Pittsburgh. AP

President Barack Obama wipes his face while greeting people after speaking at Carnegie Mellon University in Pittsburgh, Pa. , Friday, July 6, 2012. Obama is on a two-day bus trip through Ohio and Pennsylvania. AP

President Barack Obama greets supporters after a stop at Carnegie Mellon University in Pittsburgh, Friday, July 6, 2012. Obama is on a two-day bus campaign trip through Ohio and Pennsylvania. AP

President Barack Obama speaks at Carnegie Mellon University in Pittsburgh, Pa. , Friday, July 6, 2012. Obama is on a two-day bus trip through Ohio and Pennsylvania. AP

The motorcade with President Barack Obama makes it way through Ohio, Friday, July 6, 2012. Obama is on a two-day bus trip through Ohio and Pennsylvania. AP

Security personnel take positions on the rooftops on campus as President Barack Obama arrives at Carnegie Mellon University in Pittsburgh, Friday, July 6, 2012. Obama is on a two-day bus campaign trip through Ohio and Pennsylvania. AP

President Barack Obama walks from his bus as he stops to get pie and cookies in Beaver, Pa. , Friday, July 6, 2012. Obama is on a two-day bus trip through Ohio and Pennsylvania. AP

President Barack Obama gives a thumbs up as he greets the crowd after speaking at Dobbins Elementary School in Poland, Ohio, Friday, July 6, 2012. Obama is on a two-day bus trip through Ohio and Pennsylvania. AP

From left, Jim DiFalco, and Rick Nixon, of Tallmadge, Ohio, President Barack Obama and Keith Ross, of Norton, Ohio talk during a breakfast stop at Ann's Place in Akron, Ohio on the president's two-day campaign bus trip in Ohio and Pennsylvania on Friday, July 6, 2012. AP

US President Barack Obama (L) smiles as he departs the Bergman Orchards Farm Market in Port Clinton, Ohio, July 5, 2012, where he made an unannounced visit to speak with supporters while on a bus tour of Ohio and Pennslyvania. Getty

President Barack Obama greets the crowd after his speech at Washington Park in Sandusky, Ohio, Thursday, July 5, 2012. Obama is on a two-day bus trip through Ohio and Pennsylvania. AP

President Barack Obama greets the crowd before heading to the stage to speak at an ice cream social at Washington Park in Sandusky Ohio, Thursday, July 5, 2012. Obama is on a two-day bus trip through Ohio and Pennsylvania. AP

U.S. President Barack Obama speaks at a campaign event at the Wolcott House Museum Complex July 5, 2012 in Maumee, Ohio.  Getty

US President Barack Obama (2nd R) walks to his campaign bus as he arrives at Toledo Express airport in Toledo, Ohio, July 5, 2012.  Getty

President Obama walks on the tarmac after arriving on Air Force One at Toledo Express Airport in Swanton, Ohio, Thursday July 5, 2012, for the start of his bus tour. AP

US President Barack Obama boards Air Force One at Andrews Air Force Base in Maryland on July 5, 2012 en route to Toledo, Ohio, to attend campaign events. Getty [Green lens is an IRCM anti-missile detector, one located above each of the four engines.]

US President Barack Obama exits his limo at Joint Base Andrews, Maryland, to board Air Force One July 5, 2012 en route to Toledo, Ohio, to attend campaign events. Getty

U.S. Secret Service agents on post as U.S. President Barack Obama delivers remarks to an Independence Day picinic on the South Lawn of the White House on July 4, 2012 in Washington, D.C. On this Independence Day President Obama is hosting a 4th of July celebration picnic on the South Lawn for White House staff and US service members. Getty [Agents hold "hands ready" quick-response position.