I think this is a socioeconomic issue and not racism. Most illegal immigrants are underprivileged Mexicans and they came here because they don’t have access to good job and or education at home. Naturally these illegal immigrants gravitate toward more affordable areas joining other poor and less educated Americans. The best predictor of educational success of a student is his or her parent’s educational attainment. So it is not surprisingly that schools in these poorer areas fail to meet the minimum standard that many parents want.
If I have children I want them to go to the best schools I can afford. Right now these better equipped schools with good test scores happen to be in Poway or Carmel Valley areas and not in Chula Vista.