In the next place, Mr. President, I contend that there is a supreme law of the land, consisting of the Constitution, acts of Congress passed in pursuance of it, and the public treaties.  This will not be denied, because such are the very words of the Constitution.  But I contend, further, that it rightfully belongs to Congress, and to the courts of the United States, to settle the construction of this supreme law, in doubtful cases.  This is denied; and here arises the great practical question, Who is to construe finally the Constitution of the United States?  We all agree that the Constitution is the supreme law; but who shall interpret that law?  In our system of the division of powers between different governments, controversies will necessarily sometimes arise, respecting the extent of the powers of each.  Who shall decide these controversies?  Does it rest with the general government, in all or any of its departments, to exercise the office of final interpreter?  Or may each of the States, as well as the general government, claim this right of ultimate decision?  The practical result of this whole debate turns on this point.  The gentleman contends that each State may judge for itself of any alleged violation of the Constitution, and may finally decide for itself, and may execute its own decisions by its own power.  All the recent proceedings in South Carolina are founded on this claim of right.  Her convention has pronounced the revenue laws of the United States unconstitutional; and this decision she does not allow any authority of the United States to overrule or reverse.  Of course she rejects the authority of Congress, because the very object of the ordinance is to reverse the decision of Congress; and she rejects, too, the authority of the courts of the United States, because she expressly prohibits all appeal to those courts.  It is in order to sustain this asserted right of being her own judge, that she pronounces the Constitution of the United States to be but a compact, to which she is a party, and a sovereign party.  If this be established, then the inference is supposed to follow, that, being sovereign, there is no power to control her decision; and her own judgment on her own compact is, and must be, conclusive.

I have already endeavored, Sir, to point out the practical consequences of this doctrine, and to show how utterly inconsistent it is with all ideas of regular government, and how soon its adoption would involve the whole country in revolution and absolute anarchy.  I hope it is easy now to show, Sir, that a doctrine bringing such consequences with it is not well founded; that it has nothing to stand on but theory and assumption; and that it is refuted by plain and express constitutional provisions.  I think the government of the United States does possess, in its appropriate departments, the authority of final decision on questions of disputed power.  I think it possesses this authority, both by necessary implication and by express grant.