Is teaching in only English to all students discrimination or assimilation?
Is teaching in just a single language [English] for all students in American public education a form of “institutional discrimination” against those immigrant children from non-English speaking countries (especially if they have to pass standardized tests to exit high school) or does it accelerate their assimilation into and success in the American society?
Teaching only in English is not discrimination. It is a necessary form of assimilation. Students can, in general, not succeed in the United States without being pretty fluent in English. Therefore, whatever sort of education gets them to fluency (or at least competency) most quickly is the thing that is best for them.
That said, there is a great deal of conflict on this issue. Scholars are not able to agree on whether bilingual education is or is not more effective than immersion in English. This can be seen quite clearly in this link. My experience makes me feel that bilingual education is less effective than immersion. I feel that bilingual education often "babies" kids along instead of throwing them in and forcing them to learn English as quickly as possible. I have also seen it, I think, create a sense of tension between ELL kids and mainstream kids. This is not helpful at all.
So, I am not an expert on this, but even the experts can't agree. My experience tells me that bilingual education is not great and that immersion in English is much more of a tool for assimilation than a form of discrimination.
I don't believe that teaching in only English is discrimination because English is the first language in America. Although most immigrant children coming to high school may sometimes speak another language, it is important that they learn the english language as a survival mechanics. Most non english speaking immigrant children will learn the language of parents before they learn how to speak english. If they are to leave in America and make a living for themselves then they need to be equip with the english language to help them along.
Even if non english speaking immigrant children assimulate into the American culture and speak english they are not going to totally forget their other language because most of the adult in their life will not be able to communicate in English.
They need to learn English because to survive in a foreign country, they need to be able to communicate with people and also they can use their english to help communicate for their parents.