If you’ve ever wondered how it’s possible that the U.S. has the highest rate of mass incarceration in the world — the majority being African-American — filmmaker Ava DuVernay makes its dazzlingly clear with her new documentary 13TH. Perhaps the most damning discovery in the film is that there is a clause in the 13th Amendment of the Constitution, the one granting freedom to slaves, that excludes prisoners from said freedom. It’s easy to see, then, how people of color were forced back into legal slavery via incarceration.

“A lot of folks kind of miss that part of the amendment, because it’s in a pretty major amendment that says, ‘Slaves are free! Except this part,’ at the end. And so it’s been missed. But that ‘except this’ has been exploited by politicians and the power structure for many, many generations, and so it’s time that the rest of us take a look at it,” DuVernay told REVOLT.

With a mixture of archival footage and interviews with activists, politicians, historians, and formerly incarcerated persons, DuVernay shows the carefully orchestrated racial inequalities of the American prison system and its effects on the larger communities of color. Just as important, 13th illustrates how both political parties have contributed to the horrors of mass criminalization. DuVernay draws a through line to the rhetoric being used in the current election season by the presidential candidates, making it a timely documentary to watch before you visit the polls.

13th hits Netflix today (October 7). Watch our interview below:

Insider Access | Ava DuVernay talks mass incarceration and Black Lives Matter