“But the Constitution has not only conferred these high powers upon Congress, but it has adopted effectual means to restrain the States from interfering with their exercise. For that purpose it has in strong prohibitory language expressly declared that ‘no State shall enter into any treaty, alliance, or confederation; grant letters of marque and reprisal; coin money; emit bills of credit; make anything but gold and silver coin a tender in payment of debts; pass any bill of attainder, _ex post facto_ law, or law impairing the obligation of contracts.’ Moreover, ‘without the consent of Congress no State shall lay any imposts or duties on any imports or exports, except what may be absolutely necessary for executing its inspection laws,’ and if they exceed this amount, the excess shall belong to the United States. And ‘no State shall, without the consent of Congress, lay any duty of tonnage, keep troops or ships of war in time of peace, enter into any agreement or compact with another State, or with a foreign power, or engage in war, unless actually invaded or in such imminent danger as will not admit of delay.’ “In order still further to secure the uninterrupted exercise of these high powers against State interposition, it is provided ‘that this Constitution and the laws of the United States which shall be made in pursuance thereof, and all treaties made or which shall be made under the authority of the United States, shall be the supreme law of the land; and the judges in every State shall be bound thereby, any thing in the Constitution or laws of any State to the contrary notwithstanding.’ “The solemn sanction of religion has been superadded to the obligations of official duty, and all Senators and Representatives of the United States, all members of State Legislatures, and all executive and judicial officers, ‘both of the United States and of the several States, shall be bound by oath or affirmation to support this Constitution.’