It's a limited trump card, in that a jury can nullify law but not make it, or even adjust the charge. And their decision holds no legal precident beyond the immediate case.
I think of an informed jury as the tire between the wheel and the road, to fill the gap between the abstract judgement of the legislature and the concrete particulars. Tires do fail, sometimes fatally, but they save a lot of wear on the whole system.
The one case I was a juror on, there were questions about specific details of the charge vs the standard for a conviction on that charge. We couldn't get clarification because the judge decided to go home at 4:30, 40 minutes into deliberations.
No one wanted to come back to deliberate another day, so we convicted on the counts we were sure of and acquitted on the remainder. The aggravated details made no sense as the verdicts were read as they ended up being grossly inconsistent. In the end, the defendant was sentenced to 6 years. It could have been 60 years if the judge had hung around though.
In the Anglo-American tradition, juries cannot nullify, make, or frankly do anything else with law. What they can do is decide the facts. Jury nullification is the jury legally denying the facts, no matter how observably true they are. Because legally speaking the jury determines the facts, that’s that. A judge can overrule a guilty verdict, but not an innocent one.
I think of an informed jury as the tire between the wheel and the road, to fill the gap between the abstract judgement of the legislature and the concrete particulars. Tires do fail, sometimes fatally, but they save a lot of wear on the whole system.