I am thinking about that English-only requirement was not repealed until 2016, by Proposition 58 in California. I was aware in the 2015–16 school year, there were approximately 1.37 million English learners in California public schools, according to the official website of California Department of Education. This massive amount of English learners, including recent immigrants, had no choice, but to stay in the English-only classroom. Being aware that it is such a recent policy to allow non-English languages in public education, I am interested in learning the reasons behind this and evidence of supporting English-only instructions.
(Yinxuan Gu)