I'll take your question on good faith that you genuinely want an answer and you're not trolling, and talk about Detroit.
Families with a breadwinner in the auto industry, for example, often did very well, living the American Dream.
But in other cases, generations of family members never graduated from high school, thus never went to college. The reasons for that are many, including environment, lack of role models who graduated, and low income.
A lot of pundits want to blame one thing like "lack of personal responsibility", but like most simplistic statements about complex things, it's not helpful.
I wouldn't use the words "white supremacy." I would say that after understanding the issues, those in power and with power could do more. The political leadership in Detroit hasn't been white for decades, so it's really a general leadership issue.
For example, if you want more college graduates, then you fully fund school lunch programs and tutors as a start. Then after that, you look at the remaining problems, and you iterate on those in a sustained manner for 50 years.