Texas lawmakers are advancing legislation that would authorize state police to apprehend and deport illegal immigrants. The legislation, the Sun’s Maggie Hroncich has reported, has triggered a debate over the authority of a state to deal with immigration issues considered by many to be the exclusive responsibility of the federal government.

In 2012, the Supreme Court, in Arizona v. United States, ruled that it was unconstitutional for states to arrest and deport illegal immigrants. However, that case is distinguishable from what is happening in Texas. It dealt with state officials who sought to join in the enforcement of federal immigration laws.

The crisis that confronts Texas is different. Here, the federal government has forsaken its constitutional responsibility to enforce federal immigration laws. Texas has chosen to exercise the sovereign state authority reserved to it under the Constitution — and also, in Texas’ view, a constitutional obligation.

This is marked in Article 4, Section 4, which includes the famed guarantee and protection clauses. “The United States,” the Article says, “shall guarantee to every State in this Union a Republican Form of Government, and shall protect each of them against Invasion; and on Application of the Legislature, or of the Executive (when the Legislature cannot be convened) against domestic Violence.”

From the first, the Framers saw protection against external threats as a responsibility of the national government. As they stated in Article III of the Articles of Confederation: “The said States hereby severally enter into a firm league of friendship…for their common defense…against all…attacks made upon them….” The Constitution reaffirmed this responsibility, stating in its Preamble that a fundamental purpose of the new federal government was to “provide for the common defense.” 

The Framers were keenly aware that the country faced a wide variety of external threats. As 25 Federalist puts it: “The territories of Britain, Spain, and of the Indian nations…encircle the union….” The word “invasion” contained in Article IV, Section 4 encompasses threats posed by non-state actors as well as the organized forces of a foreign government.

The Constitution delegates to the federal government a range of enumerated powers so that it can fulfill its responsibility to provide for the common defense and protect the states against invasion. But this delegation of authority is non-exclusive. Feature how emphatically this was marked — including the capitalization for emphasis — in 32 Federalist:

“​​An entire consolidation of the States into one complete national sovereignty would imply an entire subordination of the parts; and whatever powers might remain in them, would be altogether dependent on the general will. But as the plan of the convention aims only at a partial union or consolidation, the State governments would clearly retain all the rights of sovereignty which they before had, and which were not, by that act, EXCLUSIVELY delegated to the United States.

“This exclusive delegation, or rather this alienation, of State sovereignty, would only exist in three cases: where the Constitution in express terms granted an exclusive authority to the Union; where it granted in one instance an authority to the Union, and in another prohibited the States from exercising the like authority; and where it granted an authority to the Union, to which a similar authority in the States would be absolutely and totally CONTRADICTORY and REPUGNANT.”

Immigration is a perfect example of this. As governments with rights of sovereignty, each state retains the right to defend itself against invasions.  Article I, Section 10, Clause 3 makes that clear: “No state shall, without the consent of Congress…engage in war, unless actually invaded, or in such imminent danger as will not admit of delay.” Thus, if the federal government fails to fulfill its Article IV, Section 4 responsibility to protect a state, that state is fortunate to have signed a constitution that reserves to it sovereign powers..

That is done pointedly in Article 1, Section 10, the section of the Constitution that lists what the states may never do. “No State shall, the 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.”

One could call it the “unless” clause. Our constitutional history is clear. The terms “invasion” and “danger” encompass threats posed by irregular forces and lawless bands like Indians and pirates, and just like those that now threaten Texas. The Lone Star State has the sovereign right to defend itself against those threats because the federal government has failed to do so.

The Texas Constitution confirms this interpretation. The powers of the Governor enumerated in Article IV, Section 7 include the power “to repel invasions.” The record of the 1875 convention that produced the Texas Constitution makes it clear that the word “invasion” covers all manner of attacks across the border and that, as one delegate put it, any time the federal government fails to protect the border, then it will “devolve upon the commonwealth to do so….” It is time for the sovereign state of Texas to do so.