I'm a recently retired high school teacher here in Miami. At our school, we had 30 different languages represented. The only group catered to was in the "English for Spanish Speakers" class. One of my students, a legal immigrant from China, had no choice but immersion and she did just fine. Matter of fact, she asked me to be her Godmother because she wanted an English-speaking "Mom". Today, I'm proud to say she's a US citizen and is in pharmacy school.
I don't think that we need to have a whole cottage industry in English to Spanish books, classes, teachers. I'd much rather have the bucks spent on Civics courses.