I consider, then, the power to annul a law of the United States, assumed by one State, _incompatible with the existence of the Union, contradicted expressly by the letter of the Constitution, unauthorised by its spirit, inconsistent with every principle on which it was founded, and destructive of the great object for which it was formed_. After this general view of the leading principle, we must examine the particular application of it which is made in the ordinance. The preamble rests its justification on these grounds: It assumes as a fact that the obnoxious laws, although they purport to be laws for raising revenue, were in reality intended for the protection of manufactures, which purpose it asserts to be unconstitutional; that the operation of these laws is unequal; that the amount raised by them is greater than is required by the wants of the Government; and, finally, that the proceeds are to be applied to objects unauthorized by the Constitution. These are the only causes alleged to justify an open opposition to the laws of the country and a threat of seceding from the Union if any attempt should be made to enforce them. The first virtually acknowledges that the law in question was passed under a power expressly given by the Constitution to lay and collect imposts; but its constitutionality is drawn in question from the _motives_ of those who passed it. However apparent this purpose may be in the present case, nothing can be more dangerous than to admit the position that an unconstitutional purpose entertained by the members who assent to a law enacted under a constitutional power shall make that law void. For how is that purpose to be ascertained? Who is to make the scrutiny? How often may bad purposes be falsely imputed, in how many cases are they concealed by false professions, in how many is no declaration of motive made? Admit this doctrine, and you give to the States an uncontrolled right to decide, and every law may be annulled under this pretext. If, therefore, the absurd and dangerous doctrine should be admitted that a State may annul an unconstitutional law, or one that it deems such, it will not apply to the present case.