Explain Alexanders’ social meaning of slavery as exploitation, Jim Crow as subordination and Mass Incarceration as marginalization?

The main theme of Alexander's work is that the current American system of mass incarceration, created in response to the rise in drug arrests, is a systematic attempt to marginalize people of color much in the same way that the Jim Crow laws targeted blacks in the late-nineteenth and early-twentieth centuries. Those in prison and those released are part of a system that disenfranchises them; makes it incredibly difficult to find work, housing, or other public assistance; and bestows upon them a shame and stigma that can be nearly insurmountable. As the drug war was racially motivated, the comparison to the historical Jim Crow is fitting and undeniable. It is the new racial caste system, entrenched yet invisible.