I would guess that illegals make up a large proportion of the group targeted.
I bet the school just looks the other way.
That, and of the documented population, traditional minorities make up 66% of PG County. This matters only insofar as they have been traditionally poorer, or that they have been clients of the Democrat entitlement/dependence mindset. PG county directly abuts Washington, DC, where good jobs and benefits are available to many. However, housing in PG County is expensive. The same database linked above says 9.2% of PG population was below the poverty line in 2004. With the recent ballooning of home prices, fuel costs and taxes, there may be great stresses on the poverty class.