There yet remains to be performed, Mr. President, by far the most grave and important duty which I feel to be devolved upon me by this occasion. It is to state, and to defend, what I conceive to be the true principles of the Constitution under which we are here assembled. I might well have desired that so weighty a task should have fallen into other and abler hands. I could have wished that it should have been executed by those whose character and experience give weight and influence to their opinions, such as cannot possibly belong to mine. But, sir, I have met the occasion, not sought it; and I shall proceed to state my own sentiments, without challenging for them any particular regard, with studied plainness, and as much precision as possible. I understand the honorable gentleman from South Carolina to maintain that it is a right of the State Legislatures to interfere whenever, in their judgment, this government transcends its constitutional limits, and to arrest the operation of its laws. I understand him to maintain this right, as a right existing under the Constitution, not as a right to overthrow it on the ground of extreme necessity, such as would justify violent revolution. I understand him to maintain an authority on the part of the States, thus to interfere, for the purpose of correcting the exercise of power by the General Government, of checking it and of compelling it to conform to their opinion of the extent of its powers. I understand him to maintain, that the ultimate power of judging of the constitutional extent of its own authority is not lodged exclusively in the General Government, or any branch of it; but that, on the contrary, the States may lawfully decide for themselves, and each State for itself, whether, in a given case, the act of the General Government transcends its power. I understand him to insist, that, if the exigencies of the case, in the opinion of any State government, require it, such State government may, by its own sovereign authority, annul an act of the General Government which it deems plainly and palpably unconstitutional.