If the system is white supremacist, why do Asians, Jews, Nigerians, etc. out perform whites? Why are there any variations in weath between anyone, or intra-race?

The fact of the matter is, this is all immaterial. The most logical and least racist way to combat the inequality is to give assistance to the less fortunate, regardless of their race, gender, religion, etc. Otherwise, you're just being racist.