I largely agree- especially yes, we do have to fix poverty itself if we want to fix the disturbing racial skew in our justice system. However, when I think about the wars on drugs and terror, I think that they are heavily supported by xenophobia and racism. I don't think incredibly highly of the voting public in general, but it strikes me that there might be a much greater voter pushback against our foreign interventions if they were occurring in predominantly white countries, and prominently affecting white people.
I think similarly of the war on drugs. Sure, we absolutely need to fix the precursors to addiction and the things that keep it entrenched, in order to keep black people from being victimized by addiction and imprisonment at such a high rate, but isn't the fact that this obviously unjust, bastardized, and warped form of health policy is at all acceptable to many voters, partially because a lot of white voters don't see it as affecting their communities (even though it definitely does, trust me).
You can say the same thing about the basic conditions of poverty- if a huge chunk of the population did not identify the injustices faced by those who are impoverished as "black people problems", and if the other enormous chunk of americans didn't identify them as "white trash and black people problems", maybe our policies about for-profit schools, food stamps, and HUD, would look a little more promising.
I'll lay my cards on the table, I believe that most structural exploitation occurs on an economic basis, for economic reasons. I think economic class is the primary stratification that supports most of our unjust political structures. However, it is also clear to me that, at an ideological level, these unjust measures hide themselves behind racial boundaries and political borders, so they can remain palatable to those who might have the power to change them. In other words, racism wasn't a motive, but it is a hell of a shield.