However derogatory to the sovereignty of the States the possession of such authority may seem and be, it is evidently a necessary feature of our dual system of government. In some way it was indispensable to provide for maintaining the full powers of the United States against encroachments by State legislation, and also for enforcing all the special limitations on the powers of State legislation which the Constitution of the United States lays down. This could have been done effectually in but two ways: either by giving to Congress or to the President a veto upon State laws; or by leaving the right of control to lie dormant until a necessity for exercising it should arise, and then putting it in the hands of the judiciary. The latter method was clearly open to the least objection.[Footnote: See Hamilton's discussion on this point in the _Federalist_, No. LXXX.] Jefferson maintained that there was a third, and one which the Constitution expressly provided. This was the calling of a convention of all the States for proposing amendments to it. If, he said, a State on the one hand by her highest authorities asserts a certain line of action to be within her powers, and the United States by their highest authorities deny it, "the ultimate arbiter is the people of the Union, assembled by their deputies in convention, at the call of Congress, or of two-thirds of the States. Let them decide to which they mean to give an authority claimed by two of their organs."[Footnote: Letter to Mr. Justice Johnson, Tucker, "Life of Thomas Jefferson," II, 455.] There seems a plain fallacy in this proposition. The question to be decided, in case of a conflict of judicial authority, is not which doctrine ought to be adopted, but which was adopted when the Constitution was framed. To amend that instrument and make it something else could not justly be allowed to alter the effect of acts previously done. But one serious proposition has ever been made to call a national constitutional convention for any such purpose. That was by Kentucky in January, 1861, when civil war was threatened; and it was not pressed. The very delays which would be inevitable in assembling such a body were then a reason for the call, for they would give time for the "sober second thought." The plan, however, seemed and probably was impracticable. The movement toward secession had gone too far.[Footnote: Debates and Proceedings of the National Peace Convention, 45, 61, 67.]