The intriguing thing is which states have the WORSE records of this. Are they the putatively most racist states? or less racist states? and if they're not also the most racists states on other metrics, how can we know if racism is the cause?

Also, if disparities have increased from 2001 to 2010 (cops are more racist after 1 decade?) the decriminalization of pot as a medical drug (which whites flock to) would lessen their arrest rate.

Possible Thoughts:

1. high crime in poorer blacker areas means more police coverage in those areas allowing more observation and arrest

2. black people might be more likely to 'use' on the street where they are more easily observed, whereas whites use indoors at parties, places they pay money to get into etc.

Will there be any followup studies to figure out the reason? No, there won't because 'racism is the reason' is a conversation ender. One avenue of study would be to actually peruse a sampling of arrest reports for these cases and see how it is they are caught in what circumstances.

"A retired judge, Arthur Burnett Sr., with 40 years on the Superior Court of the District of Columbia, says that the police concentrate their numbers in black communities because it is easier to intervene and make arrests in "open air" drug markets found in black communities than to look in homes, basements or country clubs found in white communities. He is the CEO of the National African American Drug Policy Coalition. Burnett says some black defendants, distrustful of authorities, may lash out, use profanities or be rebellious, behavior that makes it more likely that an officer will make an arrest."