A Secret Service agent stands guard as Republican presidential candidate, former Massachusetts Gov. Mitt Romney arrives in Charlotte, N.C., Wednesday, Aug. 15, 2012. (AP Photo/Mary Alta

 

              A Secret Service agent stands guard as Republican presidential candidate, former Massachusetts Gov. Mitt Romney arrives in Charlotte, N.C., Wednesday, Aug. 15, 2012. (AP Photo/Mary Alta
A Secret Service agent stands guard as Republican presidential candidate, former Massachusetts Gov. Mitt Romney arrives in Charlotte, N.C., Wednesday, Aug. 15, 2012. (AP Photo/Mary Altaffer)