FILE - In this Nov. 19, 1988, file photo, United Farm Workers leader Dolores Huerta, center, leads a rally along with Howard Wallace, President of the San Francisco chapter of the UFW, left, and Maria Elena Chavez, 16, the daughter of Cesar Chavez, right, in San Francisco's Mission District as part of a national boycott of what the UFW claims is the dangerous use of pesticides on table grapes. Huerta, the social activist who formed a farm workers union with César Chávez and whose "Si, Se Puede" chant inspired Barack Obama's 2008 presidential campaign slogan, is the subject of a new PBS documentary. The film "Dolores" examines the life of the New Mexico-born Mexican-American reformer from her time as a tireless United Farm Workers leader and a campaign volunteer for Sen. Robert Kennedy's 1968 presidential run. (AP Photo/Court Mast, File)