We should not stigmatize opposition by calling it racist or nativist. During the Commission on Immigration Reform, we held a number of consultations on English language acquisition. Every mode of instruction has its successes and failures. A second problem is that many school districts have no way to measure whether students are progressing in either their language acquisition or their regular subjects. Often, limited English proficient students are exempt from any testing requirements.
Bilingual education is an issue that is largely diversionary.
If immigration were reduced, there would be no educational problem to grapple with. If immigration isn't reduced, it doesn't much matter whether there's bilingual education or not, since the burdens placed on local schools are only tangentially related, if at all, to the method of language instruction. It's not just that American-born children of Latin American immigrants are being taught math in Spanish, but that they are not learning America's history and songs and stories. Bilingual education of German kids in the 19th century wasn't a particularly alarming problem, because they were also waving flags on the Fourth of July and memorizing the Gettysburg Address and the state capitals. Whether instruction is in English or Spanish, today's school children are too often celebrating Cinco de Mayo and learning about marginal historical figures selected because of extraneous characteristics.