Photo: E. Jason Wambsgans/Chicago Tribune

The ACLU has a new report out on marijuana arrests and racial disparities among those arrests across the country, and the raw numbers are staggering—especially in Cook County. While it is the second-biggest U.S. county by population, the numbers still have the ability to surprise.

The biggest county in the U.S. is Los Angeles County, with a population of almost ten million; Cook County has a bit more than five million people. And Cook County had more than twice as many arrests for marijuana possession, a rate of 91 per day. Harris County, where Houston is located, has one million fewer residents, and a third as many possession arrests. (Kings County—d.b.a. Brooklyn—and the Bronx do have higher arrest rates than Cook County as a whole.)

Here's another way of looking at it.

The ACLU data doesn't have Latino arrest rates for marijuana possession for anywhere but New York and California, because it's rarely available; generally speaking, Latinos are arrested at a higher rate than whites but lower than blacks. That's what Mick Dumke and Ben Joravsky found for Chicago, when they looked at 47,400 arrests in Chicago in 2009 and 2010: 78 percent percent black, 17 percent Hispanic, five percent white. But when it comes to who is found or pleads guilty, the ratio really gets wide.