I have a couple of comments about that.
It seems clear from other jurisdictions where they've used mandatory minimums that minorities are largely overrepresented in the group that gets captured. The very nature of mandatory minimums is that it doesn't set the sentence, it just sets the minimum sentence. Very serious cases would get those penalties regardless. The only people who are affected by mandatory minimums are those who have extenuating circumstances that mitigate in the offence. The reasonable person thinks technically this is a very serious crime, but a lot of factors go on here that make this severe penalty unworkable.
Often the factors that can contribute are the circumstances of a person's life and the environment they're living in. If they're living in very difficult circumstances the potential is there, and the potential for there to be some mitigating factors is there as well, so those people are going to be captured. It's the cases we often can't even think of that have these mitigating factors that end up being subject to the effect of the bill, not the most serious ones.
At the same time, it's worth looking at other jurisdictions, and particularly Australia, and what studies there found. Australia repealed some of their mandatory minimums because the impact was so disproportionate it really shocked the conscience of the country. Both data and logic tell us that when you take the thinking out of the process, when you ignore the person, when you sentence the crime rather than the offender, you will end up with disproportionate sentencing according to particular minority groups.