Why is calhoun sure that the tariff supporters are wrong?

Under the presidency of Jackson the exercise of power by Calhoun turned out to be controversial again, provoking a quarrel between them. The tariff decree of 1828 (called by its adversaries as "abominable taxes") was the cause of the first confrontation between the vice president and the Jacksonians. Although he had been assured that the supporters of the president in the congress would oppose the measure, it was approved by the northern Jacksonians, a fact that caused him great frustration. Back in his homeland he wrote the so-called "South Carolina Exposition and Protest" ("Exhibition and protest of South Carolina"), an essay published anonymously in which he denounced the nationalist philosophy that he had supported.

His change of positions led him in turn to the theory of the concurrent majority by means of which he supported "nullity", a theory that promoted the right of states to declare a federal law unconstitutional. These arguments found their historical roots in the calls "Kentucky and Virgina Resolutions" of 1798, written by Jefferson and Madison, in which they proposed that the states could denounce the "Law of Aliens and Sedition" of that year. President Jackson was an advocate of state rights, but he considered Calhoun's theory of nullity as dangerous as it could put the Union at risk. It should be noted that the difference between Madison's arguments and those of Calhoun differed in that the latter believed that state secession was a right that they had in extreme cases, unlike the simple nullity of certain federal legislation.