OC's Dual-Immersion Classroom Movement

Earlier this month, the Westminster School District became the first in the United States to offer dual immersion classes in English and Vietnamese. Meanwhile, parents with children in the Irvine Unified School District are criticizing officials for not offering a dual-immersion program in the city's schools. These districts are following in the wake of schools from San Clemente to Lake Forest to Anaheim that have successfully offered the option of teaching kids in English and Spanish for years. In the land that birthed the anti-bilingual education Proposition 227, what can account for the rise in wanting to teach kids in multiple languages?