Gustavo Hernandez sat with his family in a large auditorium in the downtown Central Library, a pen and pad in his lap.
He had come for a free workshop, organized by the office of Los Angeles Mayor Eric Garcetti, to reapply for a federal program that grants temporary work permits to immigrants who were brought to the United States illegally when they were children.
Hernandez, 21, who crossed from Mexico with his parents in the 1990s, listened intently as Linda Lopez, a representative from Garcetti's office, sought to put the crowd at ease. "You don't have to fear," Lopez told them. "We're here to help you."
Lopez, the daughter of Ecuadorean immigrants,...