The controversial and highly protective Tariff of 1828 was enacted into law during the presidency of John Quincy Adams. The tariff was strongly opposed in the South, since it was perceived to put an unfair tax burden on the Southern agrarian states that imported most manufactured goods. The tariff's opponents expected that Jackson's election as President would result in a significant reduction of it. When the Jackson administration failed to take any action to address their concerns, the state's most radical faction began to advocate that the state declare the tariff null and void within South Carolina. In Washington, an open split on the issue occurred between Jackson and Vice President John C. Calhoun, a native South Carolinian and the most effective proponent of the constitutional theory of state nullification, the legal theory that if a state believed a federal law unconstitutional, it could declare the law null and void in the state.