Laws must be justified by something more than the will of the majority. They must rest on the eternal foundation of righteousness. That state is most fortunate in its form of government, which has the aptest instruments for the discovery of law. (Calvin Coolidge, to the Massachusetts State Senate, January 7, 1914).
Democratic theory teaches us to govern by majority rules, while still maintaining minority rights. Jury nullification epitomizes this theory and brings the law back into the hands of the people. By subjecting the laws of our nation to the approval of the masses the interests of both the majority and the minority are preserved. The doctrine of jury nullification is the power of a jury to find a defendant innocent because they believe that the law itself is unjust, or is unjust in a particular application, and should therefore not be applied. In other words it allows the minority the opportunity to overrule the will of the majority.
A Brief History of Jury Nullification.
Jury nullification dates as far back as the Magna Carte, in 1215. Then King of England, King John, arbitrarily ruled his people, with the ability to pass any law he saw fit. The people eventually rose up against King John and the barons of England compelled their King to "pledge that he would not punish a freeman for a violation of the law without the consent of his peers." (Iowa State Bar: Position Papers) Following the signing of the Magna Carta, English juries routinely exercised their power of nullification.
As is the case with much of American law, jury nullification was derived from English common law, and has been a topic of legal debate in this country since its independence in 1776. Early in American history, jury nullification decided the well-known seditious libel trial of John Peter Zenger. The journalist was put on trial for having criticized the royal governor of New York in his newspaper.