"Sometimes the better-educated parents take advantage of the school choice option."
There's a pattern there...parents...involved...educated... If I were planning to move to Mexico, you can make dang sure I would have my children learning Spanish before we moved, not just dumping them off and expecting the school to teach them.
The phrase "take advantage of" subtly implies that the parents are doing something underhanded, subverting the law for their own fiendish purposes. In fact, the law was expressly designed to give parents the "bail" option.
My college roomie is a high school teacher, and a pretty good one, I think. He tells me that the single most important factor in student success is parental involvement. Race, gender, income... they are all less reliable indicators of student success than parental involvement.
I have nothing to back that up other than his anecdotal stories, but I tend to think it's true.