The article mystifies me from a global perspective. Americans to me seem obsessed with upward mobility. The "American Dream" is a dream of upward mobility, for goodness sake.
Why do we resent taxes on the rich, even when we're poor? Because we expect one day that we might be that rich person. One's skin color or religion is largely irrelevant in the US compared with the amount of money that you have. This is not the truth in many places.