FWIW, not all immersion programs in the US are charter based. Our kids went to a public non-charter Spanish immersion school K-8 here in San Jose, and entry into the school was split equally between native English and native Spanish speakers. That meant there was good diversity in socio-economic backgrounds without any direct "racial profiling". (Note there were also some upper-income native Spanish speakers in the program, mostly kids of immigrants from Spain and South America.)