Jury nullification isn't kind of legal precept, it's just something that logically can't be made illegal in a jury system. And it protects the genuinely guilty as much as it could protect those persecuted by the state. Moreso even, since all the worst attitudes are in-line with the state's behavior and more noble uses are likely to be rejected by dumbasses who believe in the system.
There is no analogue in American law to what martinuzz is talking about. I'm not sure if there's even an analogue to that outside the Netherlands period - "convict but don't punish" is something I've only ever heard of in the context of Dutch law. It's not an attitude you'll see among American judges. For them, not submitting to a plea deal and actually being convicted in trial is justification to punish people all the harder. The closest thing you see to this is if the accused couldn't pay bail and was stuck in prison for years before being convicted of something relatively minor, in which case their sentence might be overlapped by time served and see them freed at the time of conviction. Though plenty of judges would just give a term that they know significantly outstrips the time served to ensure they stay in prison.
You will not get leniency in an American court if you aren't rich, especially since you need a lawyer who knows to invoke most of your legal rights in the correct way. You can get away with not being white if you're rich, but only just. If you're not rich or white, the fact that you made it to trial alive puts you above a lot of other people, even though you are probably going to get the maximum allowed punishment.