Mass incarceration and drug-related crime go hand in hand. Needlessly harsh mandatory minimums for even minor drug offenses have resulted in a wave of mass incarceration, which has strengthened the prison industrial complex and empowered it to lock even more Americans in jail. Consequently, the prison system is overcrowded with a disproportionate number of African Americans with minor drug charges on their records. Today, people caught with illegal drugs are more likely to spend their entire lives in prison than rapists and murders.

The New Jim Crow is at heart a work of historical analysis tracing the development of today's mass incarceration phenomenon. This isn't a sudden occurrence, Alexander argues. It is instead the racist byproduct of the War on Drugs, which is itself a systematic effort to incarcerate rather than educate or rehabilitate offenders. Consequently, the number of inmates increased from about 300,000 in 1980 to over two million in 2000, with the rate of incarceration for African Americans growing to twenty-six times its original rate. Various "three strikes" rules have resulted in a disproportionate number of African American inmates being convicted of petty drug crimes and sentenced to needlessly harsh terms in prison. One such example comes from the case Harmelin v. Michigan, in which the court upheld a life sentence for a man who attempted to sell 672 grams of cocaine.

Money is perhaps the main reason that young African American men turn to drugs and drug-related crime. Many of them live in poor neighborhoods and grow up without their fathers, who are trapped in the criminal justice system. Without means of supporting themselves or their family, these men turn to drugs, having few options for lawful or gainful employment. Once in the criminal justice system, it becomes even more difficult for offenders to find legitimate work. When filling out job applications, they are required to check a box labeling them felons, which shuts them out of many industries. Furthermore, felons do not have access to welfare programs such as food stamps or public housing, making it near impossible for them to support themselves financially on the meager wages they earn. These obstacles often lead former offenders back to a life of crime.

Racism is both a theme and one of the primary subjects of The New Jim Crow. Michelle Alexander's central thesis is that racism and prejudice have resulted in a biased criminal justice system that takes us back to the years of Jim Crow. We are living in a "new Jim Crow" era wherein African Americans are selectively and undeniably discriminated against on the basis of their race. This is a direct result of the racial profiling police officers do, which is itself a facet of the War on Drugs. By labeling the majority of black youth criminals even before they engage in criminal activity, the government and the police have successfully created a system that condones discrimination against black people.

Systemic or "institutionalized" oppression is defined as the widespread mistreatment and oppression of a group of people, as reinforced and condoned by society and its numerous institutions, including but not limited to its criminal justice system and its social welfare programs. Systemic oppression is present in all facets of society and affects many different groups. Alexander focuses on the systemic oppression against African Americans, analyzing how the Jim Crow laws of the Reconstruction and post-Reconstruction period set the groundwork for today's fundamentally prejudiced society. If you look, it is easy to find oppression in the laws allowing police officers to stop and frisk people based solely on the color of their clothes (a pretense used to stop African Americans, who are assumed to be gangsters even when they're not).