I don't know what you mean by the term "opportunity". A kid from a Chicago slum, does have the opportunity to attend a free public high school situated in his neighborhood slum, just like a kid in the upscale town of Newton, Ma has the opportunity to attend the free public high school in Newton.
Big deal! Please don't try and compare the two public schools. While the kid from Newton stands a good chance of attending Yale or Harvard, the kid from the Chicago school stands a slight chance of being prepared to attend any college in Chicago or elsewhere.
Don't even try to compare life style of a Newton kid ( father=MD, mother PhD) with that of the Chicago kid.
Opportunities exist for the upper middle-class and the super-rich. For the poor , however, opportunities come as freely as blood from a rock.
Poor ( with their limited array of "opportunities"),who finally make it to the upper-middle or upper classes, never lose, however, that sticky, stinking dust left behind by poverty.