University graduates routinely show great emotion (spontaneous and sometimes scripted) as they stand in front of crowds to mark momentous occasions. Onlookers clap and cheer, hoot and holler, and then wait to see what the next student (or student body) will do. But one UC San Diego student's Mexican flag-waving exuberance has sparked a conversation that's transcended her brief moment Sunday. Indira Esparza, a 22-year-old undocumented student who moved to the U.S. when she was 2, proudly unfurled the green, white and red flag of Mexico as she walked across the stage.