San Antonio - Julian Castro, the telegenic former mayor of San Antonio, Texas and Obama-era cabinet member, launched his bid to become the nation's first Hispanic president Saturday, emphasizing a message of hope and diversity at a time when Americans are locked in angry debate over immigration and border security.

Former mayor of San Antonio, Texas and Obama-era cabinet member Julian Castro is expected Saturday to launch his bid to become the nation's first Hispanic president, scheduling his announcement in a border state central to America's immigration debate.