Earlier quoted context omitted.
> Likewise, whites are more likely to use low-penalty drugs like hallucinogens, and blacks are more likely to use high-penalty drugs like crack cocaine. Why is it, then, that crack cocaine is a high-penalty drug, and hallucinogens are low-penalty drugs? (I leave this as an exercise to the reader.)
Crack is highly physically addictive. People aren't out robbing houses to get their next acid fix.
Powder cocaine is literally the same drug as crack cocaine, yet the sentencing disparities since the 1980s have been completely out of sync. They've slightly converged in the last ~5 years (crack cocaine sentences have been reduced), but let's not pretend that the sentencing laws[0] have not been radically influenced by perceptions of associations of drugs with race.
> People aren't out robbing houses to get their next _____ fix
LSD is not physically addictive, but in general, I'll encourage you to question this line of thinking. Looking at whether people are "out robbing houses" glosses over the question of why people would commit robbery in order to purchase drugs, and the racial and socioeconomic issues that are inextricably linked to that.
Put another way: who's not committing robbery in order to purchase the drugs that they use, and why aren't they? Is it because their drug (e.g. powdered cocaine) is fundamentally less addictive? Or is it because they are already in a position in society that allows them other opportunities to finance their drug use? Is it a statement about the drug itself, or simply a statement about the social structures that already exist?
[0] If you want a really wonderful example of this, look at the reason that possession of <27g of marijuana was the only drug that was exempted from the Rockefeller drug laws' mandatory minimum sentencing. It was, quite literally, that kids in predominantly white and wealthy suburbs were being sentenced to prison time, and the parents wanted the judges to have discretionary power when sentencing them.