To all the communist scum who are lawyers or judges who say there is no legal basis for jury nullification, here are words directly from Jefferson.
"If the question before them be a question of law only, they decide on it themselves; but if it be of fact, or fact and law combined, it must be referred to a jury. In the latter case, of a combination of law and fact, it is usual for the jurors to decide the fact, and to refer the law arising on it to the decision of the judges. But this division of the subject lies with their discretion only. And if the question relate to any point of public liberty, or if it be one of those in which the judges may be suspected of bias, the jury undertake to decide both law and fact."
"In truth, it is better to toss up cross and pile in a cause, than to refer it to a judge whose mind is warped by any motive whatsoever, in that particular case. But the common sense of 12 honest men gives still a better chance of just decision, than the hazard of cross and pile."
Thomas Jefferson: Writings
Autobiography | Notes on the State of Virginia | Public and Private Papers | Addresses | Letters
ISBN: 978-0-94045016-5
pg 256
So it's not just the duty of a jury to judge the facts of the case, or even the law. It is the jury's duty to judge the facts, the law, AND the judge. Any case where the jury was not notified of their duties should be probably be null and void.
This and Madison's book should be required reading in school. I don't remember reading any of the founding fathers important writings in school.