My apologies, your response made it seem like you were ignoring key factors in the question.
> If the basis for the disparities is criminal intent, then we wouldn't have seen the 2 year sentence for stealing 10 million dollars that is under discussion.
Look at your state's sentencing guidelines for larceny. To use California's as an example, it doesn't matter if I steal $20 (petty larceny) or $20M (grand theft). Either way, it's the same crime, differing only in scale, and the sentencing guidelines proscribe probation to 3 years in prison, depending on the severity. Thus, a 2 year sentence for stealing 10 million dollars is an expected outcome. That is the punishment for larceny with criminal intent. Not having criminal intent gets its own category (receiving of stolen property) and sentencing of up to 1 year. 2 years is a long time to be institutionalized; it's not a trivial sentence. We often lose sight of that.
If I choose to muck things up by bringing a weapon into the mix and turning it into aggravated assault or robbery, the sentencing changes drastically. Nobody wants aggravated crime in their neighborhood, but we can tolerate a Madoff or Shkreli on the streets, even if their net damage is worse. This isn't about race or class, it's about what type of offender is less likely to be an immediate danger to our health and safety. Can a violent offender be rehabilitated? We don't know, and nobody wants to find out. So we lock them up for 99 years and revisit the matter once they're senile.
> A mugging for $20 has less criminal intent than a $10MM white collar crime and muggings kill far fewer people every year than drunk drivers.
You're comparing three different things. Theft is theft. If you intend to steal anything, it's criminal intent. Threatening your victim or pointing a gun at them demonstrates even more criminal intent. Drunk drivers have no intent, they are drunk.
As destructive as drunk driving is, I meant what I said about everybody wanting more restrictive sentences until they find themselves on the wrong end of these laws. It doesn't take much to get charged with DUI, and even if nobody got hurt it's still career-ending. You did something you shouldn't have, there were no victims, but your life is now radically altered for the worse. It boils down to a tragically negligent decision, not criminal intent, which is why in the best of cases you end up on probation with misdemeanor charges and losing your job, in other cases Joe Sixpack hitting a pedestrian gets sentenced for manslaughter and the guy who deliberately drove into protesters is facing murder charges. There are distinct differences in intent and consequences for our actions. We sentence in line with them.
I'd agree that the sentencing for DUI fatalities is lighter than it should be (as it lets politicians and debutantes off the hook when they get caught themselves), and policing of the drug wars has proven to be very clearly class- and race-driven, but I'm not seeing how disparities in sentencing guidelines are inherently discriminatory towards any demographic. The message is clear: shoplift if you must, but don't you dare stick a gun in the cashier's face. This applies to everyone.