San Antonio Mayor Julian Castro addresses the the Democratic National Convention in Charlotte, N.C., on Tuesday, Sept. 4, 2012. (AP Photo/Carolyn Kaster)

 

              San Antonio Mayor Julian Castro addresses the the Democratic National Convention in Charlotte, N.C., on Tuesday, Sept. 4, 2012. (AP Photo/Carolyn Kaster)
San Antonio Mayor Julian Castro addresses the the Democratic National Convention in Charlotte, N.C., on Tuesday, Sept. 4, 2012. (AP Photo/Carolyn Kaster)