There has been growing concern that Mexican immigration to California has reached a crisis, with immigrants taking jobs from native-born workers, using public services for which they have not paid, and living in isolation from U.S. society. This report assesses the current situation of Mexican immigrants in California and projects future possibilities. The authors constructed a demographic profile of the immigrants, examined their economic effects on the state, and described their socioeconomic integration into California society. They developed models of both the immigration and integration processes, and then used the models to project future immigration flows. The report's major conclusion is that the widespread concerns about Mexican immigration are generally unfounded: Mexican immigrants differ in their characteristics and their effects on the state; they provide economic benefits to the state, and U.S.-born Latinos may bear the brunt of competition for low-skill jobs; immigrants contribute more to public revenues than they consume in public services, but produce a net deficit in educational expenditures; and they are following the classic pattern for integrating into U.S. society, with education playing a critical role in this process.