Policy Issues / Secure Borders

The Federal Government’s Guarantee to Protect the States Against Invasion

The federal government has willfully abandoned its duty to defend the states – and the citizens who reside within them – from the ongoing invasion. However, states possess the authority, right now, to remedy Washington’s abrogation of its Guarantee Clause obligations.

Executive Summary

The United States is facing an unprecedented crisis along its southern border with Mexico. Violent transnational criminal organizations control large swaths of the border. Nearly two million illegal immigrants were apprehended by Border Patrol agents in the last year. Another estimated 400,000 individuals evaded authorities and disappeared inside the interior of the country. Federal agents have seized record amounts of fentanyl, heroin, and methamphetamines, and record numbers of Americans have died from drug overdoses and opioid poisonings. Local jurisdictions face serious strains on their resources, such as contending with crime, burdens on community resources, and exploding student numbers, particularly students with above-average needs such as English as a second language (“ESL”).

The federal government has been idle in the face of this unprecedented invasion. In some respects, federal officials have even encouraged it. This failure to protect the states against invasion is a direct violation of the Guarantee Clause at Article IV, Section 4 of the Constitution. That clause establishes three guarantees owed by the federal government to the states: the maintenance of a republican form of government in every state, protection against invasion, and protection against domestic insurrection.

The federal government has willfully abandoned its duty to defend the states – and the citizens who reside within them – from the ongoing invasion. However, states possess the authority, right now, to remedy Washington’s abrogation of its Guarantee Clause obligations.

The Guarantee Clause

The text and original meaning of Article IV, Section 4 of the United States Constitution clearly support the conclusion that all branches of the federal government, including the judiciary, are obligated to perform their respective constitutional functions so as to protect each of the states from any kind of lawless invasion that may occur. 

Article IV, Section 4 states:

“The United States 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.” (Emphasis added)

The Guarantee Against Invasion Is Unconditional

The three guarantees to the states set forth in Section 4 — to preserve for them a republican form of government, protect against invasion, and protect against domestic violence — are linked by the word “and” that is placed between each of them. Together, the guarantees form what is known in the canons of interpretation and construction as a conjunctive list structured as a polysyndeton. 

In any legal instrument, from a constitution to a statute to a contract to a will, each of the individual obligations included in a conjunctive list creates a separate and distinct duty for the obligated party. (See, Scalia & Garner, Reading Law: The Interpretation of Legal Texts, at 116-125 (Thomson/West, 2012).) This means that the binding nature of each separate obligation is independent and does not depend on the extent to which its fulfillment may also help to fulfill other obligations in the list.

Protecting a state against invasion may also help to preserve republican government for the state and forestall domestic violence within its territory. But the obligation of the federal government to protect against invasion is separate, distinct and independent from the other obligations contained in the conjunctive list set forth in Article IV, Section 4. The federal government is obligated to protect each state against invasion in every case, whenever a state is invaded in fact, or threatened with invasion. The duty is unconditional.

The Guarantee Against Invasion Is Fundamental

From the first, the Founders clearly saw that protection against external threats of invasion is a fundamental responsibility of government. Indeed, one of the most important reasons they formed our government was to provide a protective common defense against invasion. As they stated in Article III of the Articles of Confederation:

“The said [thirteen] States hereby severally enter into a firm league of friendship with each other, for their common defense, the security of their liberties, and their mutual and general welfare, binding themselves to assist each other, against all force offered to, or attacks made upon them, or any of them, on account of religion, sovereignty, trade, or any other pretense whatever. (Article III)

Under the Articles of Confederation, the U.S. Congress had the “right and power of determining on peace and war,” and hence the obligation to protect each of the states from invasion. (Article IX, paragraph 1.) The Articles were signed in 1777 and ratified in 1781. It soon became apparent that, for a variety of reasons, the form of government established by the Articles of Confederation was insufficiently vigorous to effectively protect the interests of the United States and the rights of its citizens. 

In 1787, the Founders returned to Philadelphia to “form a more perfect union” under a new Constitution that was designed to provide a more effective system of government for the nation than the one provided by the Articles of Confederation, a Constitution that, according to its Preamble, could better “insure domestic tranquility, provide for the common defense, promote the general welfare, and secure the blessings of liberty,” a constitutional government that could, among other things, more effectively protect the states against invasion.

The Guarantee Covers All Invasions

“Without some indication to the contrary, general words (like all words, general or not) [that are contained in any legal instrument] are to be accorded their full and fair scope. They are not to be arbitrarily limited.” (Scalia & Garner, at 101.) The full and fair scope of the general word “invasion” in Section 4 of Article IV includes any unwanted unlawful entry that harms or threatens to harm the interests of the state or states invaded and the citizens therein. Section 4 contains no indication to the contrary, i.e., it contains no limitation on the general word “invasion.”

Additionally, if any legal instrument is to be understood correctly and applied appropriately, “[w]ords must be given the meaning they had when the text was adopted.” (Id., at 78.) As noted above, in the Articles of Confederation, the states sought to provide “for their common defense … against all force offered to, or attacks made upon them, or any of them, on account of … any … pretense whatever.” (Article III.) They sought to provide for a common defense not only against the force offered by the army and navy of Great Britain but against any external forces that might threaten them to any degree, including but not limited to “some nation of Indians” or “pirates.” (Article VI, paragraph 5.)

The Framers of the Constitution were keenly aware that the country would continue to face a variety of external threats from every direction, threats posed by lawless bands as well as threats posed by the forces of a foreign government. “The territories of Britain, Spain, and of the Indian nations in our neighborhood … encircle the union….” (Federalist No. 25.) Given the encircling nature of the various threats, the Framers concluded that it was appropriate to entrust the common defense against invasion to the federal government. “The [encircling] danger, though in different degrees, is therefore common. And the means of guarding against it, ought, in like manner, to be the objects of common councils, and of a common treasury.” (Id.) And they argued “that [the federal] government ought to be clothed with all the powers requisite to the complete execution of its trust.” (Federalist No. 23.) 

For all these reasons, one may conclude with confidence that the original meaning of the word “invasion” contained in Article IV, Section 4 of the Constitution encompasses threats to the safety, security or well-being of the states and their citizens posed by any external group, not just those threats posed by the organized forces of a foreign government. Such threats include drug traffickers, gang members, other violent criminals, and suspected terrorists hidden among the throng of illegal immigrants that cross our undefended southern border, as well as the illegal immigrants themselves.

The Guarantee Against Invasion Extends Equally to Each and Every State

The Framers were deeply concerned that factionalism and sectionalism could undermine the new Republic, perhaps even tear it apart. They sought, through the checks and balances and other structural features they included in the Constitution, to establish a “well-constructed union” that could “break and control the violence of faction.” (Federalist No. 10.)

In his 1796 Farewell Address to The People of the United States, President Washington warned that the forces of geographical sectionalism and political factionalism, if not subordinated to common national interests, could destabilize and perhaps destroy the Republic. As he noted, “To the efficacy and permanency of your Union, a government for the whole is indispensable.” 

In extending the protection against invasion to “each” state, the Framers designed that part of Article IV, Section 4 to prevent an administration driven by sectional or factional considerations from refusing to defend certain parts of the nation or certain interests within the nation. As St. George Tucker noted, the provision guards against “the possibility of an undue partiality in the federal government in affording it’s [sic] protection to one part of the union in preference to another….” (St. George Tucker, Blackstone’s Commentaries: With Notes of Reference to the Constitution and Laws of the Federal Government of the United States, Vol. 4, at 366, (Philadelphia, 1803).)  

Analogously, in the case of illegal immigration, the provision guards against the possibility that, driven by political faction, the federal government might decide to forgo its Constitutional responsibility to protect each state against invasion – in spite of the Constitution and laws of the United States.

The Justiciability of The Guarantee Against Invasion

There is very little federal case law on the Guarantee Clause, perhaps because in a case in the mid-nineteenth century the Supreme Court held that enforcement of the federal government’s guarantee to preserve a republican form of government for every state is a political question for Congress and not a justiciable issue for the courts. (See, Luther v. Borden, 48 U.S. 1 (1849).)

In more recent cases, the Supreme Court has shown a willingness to take and decide cases involving important issues previously considered political questions outside the jurisdiction of the courts, but it has done so relying on other provisions in the Constitution. (See, e.g., Baker v. Carr, 369 U.S. 186 (1962) (redistricting justiciable under Equal Protection Clause of Fourteenth Amendment).)

Luther and the later decisions holding that Guarantee Clause disputes raised nonjusticiable political questions dealt with the federal government’s guarantee to preserve a republican form of government for the states, and not with the federal government’s guarantee to protect the states from invasion. Given the course the Supreme Court has taken since Luther, it seems likely that federal courts would entertain a lawsuit by the federal government against a state that utilized its Constitutional authority for self-protection, should the federal government choose to attempt to block such a state’s effort. However, Luther suggests that federal courts may well continue to hold that guarantee clause cases — including cases involving the protection against invasion — are non-justiciable. Thus, it is the invaded states themselves who have the power to decide when the federal government has failed to fulfill its Constitutional obligations under the Guarantee Clause. Alternatively, if the courts were to decide such a case was justiciable, the burden of proof would be on the federal government to prove that there is not an invasion of the defendant state in question — a decidedly difficult case to make under the current circumstances.

The Built-In Self-Help Provision in the Constitution to Repel Invasions

Unlike the other two guarantees in Article IV, Section 4, the federal guarantee of protection against invasion is accompanied in the Constitution with an affirmative acknowledgment of the power retained by every state to repel invasions themselves. That power is found in Article I, Section 10, Clause 3 of the Constitution.

Article I, Section 10, Clause 3 states:

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.” (Emphasis added.)

It is clear that the Guarantee Clause is intended, among other things, to guarantee each and every state federal protection against invasion, and that the current circumstances related to the southern border of the United States would qualify as an invasion from which the federal government is failing to provide its Constitutionally obligated protection. Based upon that conclusion, invaded states may undertake their own efforts to repel the current invasion using their authority to do so under Article I, Section 10, Clause 3 of the Constitution.

Finally, it must be the invaded state(s) that decide whether Article IV, Section 4 has been violated as it relates to their protection against invasion, as only such state(s) are in a position to effectuate the powers of self-protection affirmatively stated in Article I, Section 10, Clause 3.  At the time of the ratification of the Constitution, part of the value of the retention by states of the power to defend themselves was avoiding the time involved in communicating between the states and the federal government.  The legal authority to make the decision as to whether a state of invasion exists cannot change simply because of the modern availability of immediate communication – such changes do not change the meaning and original understanding of the text of the Guarantee Clause.


A clear reading of the Guarantee Clause makes clear that the federal government has a Constitutional duty to protect each of the states from invasion. Underpinned by the writings of the Framers, it is evident that what is occurring at the southern border constitutes an invasion and poses a threat to the safety, security, and well-being of the states and the citizens therein. Moreover, the federal government has clearly failed to protect the states along America’s southern border from the currently-ongoing invasion. Put differently, the federal government is currently in violation of its Guarantee Clause obligation to protect the states from invasion.