The honor roll on the wall at Toppenish Junior High tells the story: all Hispanic surnames. The large numbers of Mexican immigrant farmworkers has transformed the public school system in Eastern Washington. Newly arrived students are instructed in both Spanish and English, and in this moment, María Guadalupe Arcila, 12, receives a Spanish-English dictionary from her teacher, Margarita Tobias. In her class of about 25 children, not one has been here more than a year and all but one are from Mexico.