Please also consider the rates at which different population groups commit serious crimes, such as murder and rape. We are talking about prison populations after all - people convicted of minor drug offenses like possession are a small percent of the prison population.

The publication "Homicide Trends in the United States" by the US Department of Justice has crime data broken down by race, for example. See pages 11 and 12: https://www.bjs.gov/content/pub/pdf/htus8008.pdf

The data shows that people of different races commit serious crimes such as murder at considerably different rates.

The FBI also publishes crime statistics aggregated by race: https://ucr.fbi.gov/crime-in-the-u.s/2016/crime-in-the-u.s.-...

>In 2008, the [homicide] offending rate for blacks (24.7 offenders per 100,000) was 7 times higher than the rate for whites (3.4 offenders per 100,000)

Wow, why is that so high?

It's complex, and defies simplistic explanations (so don't believe simplistic explanations if you see/hear them).

An attempt at a nuanced explanation (which undoubtedly misses a ton of factors):

Huge disparities in overall wealth and income, coupled with geographic segregation and isolation of a lot of the black population in areas of concentrated poverty, and the associated lack of access to social goods, such as public safety and good schools. The combined effects of poverty/segregation/isolation are specifically reflected in the fact that 78% of homicides involve people who know each other [1]. People who know each other killing each other is a result of the breakdown of community structures that would disincentivize that behavior. There have to be powerful incentives for someone to kill someone that they know, considering that the potential consequences are so severe (incarceration, violent retribution, etc). Often the perpetrators have very little (in wealth, community, etc) to lose, which also increases the incentive.

Another group that are similarly economically poor, Latinos, but due to a different history, have more intact community structures, don't have as high a rate of violent crime.

[1] https://www.bjs.gov/content/pub/pdf/htus8008.pdf (Table 8)

There are many possible reasons for that besides racism. Blacks are probably more likely to be smoking on the street, carrying weed with them, etc. Also black neighborhoods are policed more heavily due to crime rates so blacks are more likely to be stopped in the first place.

In all likelihood, higher arrests for marijuana of blacks are more due to the above factors than racism, though I’m sure that’s a non-zero factor as well.

To what extent is "marijuana posession" just a proxy for more serious crimes that are harder to prove? Just like Al Capone was jailed for tax evasion...