NOT the argument Cuccinnelli and Vought made.
Known as the guarantee clause, Article IV, Section 4 of the Constitution states, “The United States shall guarantee to every State in this Union a Republican Form of Government, and shall protect each of them from Invasion; and on Application of the Legislature, or of the Executive (when the Legislature cannot be convened) against domestic violence.”
Therefore, governors, attorneys general, and state legislatures must take emergency measures–beyond the scope of what has been attempted to this point–to follow through on the primary function of government: protecting its citizens.
The Constitution provides states an appropriate “self-help” remedy under Article I, Section 10, Clause 3, which stipulates that, “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 delay.”