Even though bilingual education has provided a positive and supportive environment for the academic and social growth of many language-minority students, politically motivated opposition to bilingual education has prevailed in most states.
Conservative forces mobilized throughout the nation in the 1980s and 1990s to attack taxes, schools, and bilingual education. Since the 1990s, these same groups have frequently attacked multicultural education as divisive to national unity. Some English speakers are offended that immigrant children are taught in their native tongue for part of the day. Political leaders argue that bilingualism handicaps children.
Bilingual education is a broad term that refers to the presence of two languages in instructional settings. The term is a simple label for a complex phenomenon that depends upon many variables, including the native language of the students, the language of instruction, and the linguistic goal of the program, to determine which type of bilingual education is used. Students may be native speakers of the majority language or a minority language. The students' native language may or may not be used to teach content material. Bilingual education programs can be considered either additive or subtractive in terms of their linguistic goals, depending on whether students are encouraged to add to their linguistic repertoire or to replace their native language with the majority language. Bilingual education is used here to refer to the use of two languages as media of instruction.
Bilingual education is grounded in common sense, experience, and research. Common sense says that children will not learn academic subject material if they can't understand the language of instruction. Experience documents that students from minority-language backgrounds historically have higher dropout rates and lower achievement scores. Finally, there is a basis for bilingual education that draws upon research in language acquisition and education. Research done by Jim Cummins, of the Ontario Institute for Studies in Education at the University of Toronto, supports a basic tenet of bilingual education: children's first language skills must become well developed to ensure that their academic and linguistic performance in the second language is maximized. Cummins's developmental interdependence theory suggests that growth in a second language is dependent upon a well-developed first language, and his thresholds theory suggests that a child must attain a certain level of proficiency in both the native and second language in order for the beneficial aspects of bilingualism to accrue. Cummins also introduced the concept of the common underlying proficiency model of bilingualism, which explains how concepts learned in one language can be transferred to another. Cummins is best known for his distinction between basic interpersonal communication skills (BICS) and cognitive academic language proficiency (CALP). BICS, or everyday conversational skills, are quickly acquired, whereas CALP, the highly decontextualized, abstract language skills used in classrooms, may take seven years or more to acquire.

Cummins, J. (1981). The role of primary language development in promoting educational success for language minority students. In Leyba, C. F. (Ed.), Schooling and language minority students: A theoretical framework. Los Angeles: Evaluation, Dissemination, and Assessment Center. Rossell, C. H., & Baker, K. (1996). The educational effectiveness of bilingual education. Research in the Teaching of English, 30(1 Wong Fillmore, L. (1991). When learning a second language means losing the first. Early Childhood Research Quarterly, 6, 323–346.