Luis Valdez has written and directed such films as “La Bamba” and “Zoot Suit” for Hollywood. But in the late 1960’s he didn’t even have a theater, just a flatbed truck, a few costumes and fake moustaches, and the drive to bring theater to Mexican-American laborers. Valdez founded Teatro Campesino — the Farmworkers Theater which has entertained fruit pickers and their families for 40 years. Peter Crimmins talked to Valdez about his dream of art for the people.