Throughout his campaign, President Donald Trump referred to unlawful migration as an “invasion.” Some interpreted this language as a purely rhetorical device to drum up fear and to convey that migrants, despite all evidence to the contrary, come to the United States bent on violence and destruction. But national security and immigration lawyers knew better. With each reference to the supposed “invasion” across the United States’s southern border, we saw a growing risk that Trump would try to misappropriate wartime laws for peacetime immigration enforcement.
The truth turned out to be worse.
Trump’s migration-as-invasion theory permeates his executive orders and other pronouncements on immigration. But he is not just using the frame to try to exploit inapplicable wartime laws and constitutional authorities, as damaging as that is. In at least one of his orders, he is also using it to lay claim to vast presidential powers that don’t exist in peacetime or wartime, launching a direct assault on the constitutional separation of powers and the rule of law.
To begin, one of Trump’s Day One orders tees up a potential invocation of the Alien Enemies Act of 1798, a wartime law that can be invoked in times of “invasion.” The Act was last used in World War II to intern 31,000 noncitizens of Japanese, German, and Italian descent without due process. (U.S. citizens of Japanese descent were interned under a separate authority.) If Trump invokes the law—and if the courts uphold his invocation—it could empower him to summarily detain and deport foreign nationals who are lawfully present in the United States and have no criminal history.
This would be a clear abuse of the law. As explained in a recent report from the Brennan Center (where we work), the Alien Enemies Act’s powers are available in response to a literal armed attack, not a figurative or purely rhetorical “invasion.” The language and structure of the law, as well as the congressional debate over its enactment, leave no doubt on this point; the law refers to acts of “actual hostility” and was intended to implement the law of war. The law has been used only in times of declared war or, during World War II, in the immediate wake of Japan’s attack on Pearl Harbor.
In another Day One executive order, Trump directed the Secretary of Defense to assign a new mission to NORTHCOM, the combatant command for the U.S. armed forces in the North American continent: “repelling forms of invasion including unlawful mass migration, narcotics trafficking, human smuggling and trafficking, and other criminal activities.” The order directs NORTHCOM to plan a “campaign” for accomplishing this mission. It cites no specific statutory authority; instead, it notes the president’s “solemn responsibility” as “Chief Executive” and “Commander in Chief of the Armed Forces” to protect “the sovereignty and territorial integrity of the United States.”
Here, Trump appears to be relying on a longstanding and widely accepted interpretation of the Constitution under which presidents have inherent constitutional authority—and can act on a temporary basis without congressional authorization—to repel invasions of the United States. Like the Alien Enemies Act, however, this power is reserved for armed attacks. During the Constitutional Convention, the Founders explicitly referred to this presidential prerogative as “the power to repel sudden attacks” or “repel and not to commence war.” Nothing in the Constitution remotely contemplates a presidential power to direct a military campaign against civilians entering the country without documentation.
As alarming as these executive orders are, the most far-reaching may be the order that purports to implement the Constitution’s “Guarantee Clause,” under which the United States must protect the states against invasions. As a threshold matter, Trump’s order again characterizes migration as an invasion and therefore suffers from the same flaw as the others. The courts have affirmed that the Guarantee Clause’s protection against invasion applies in times of “armed hostility from another political entity.” It refers to the federal government’s responsibility to defend states against acts of war, not migration.
Diluting the meaning of “invasion” in the Guarantee Clause would degrade constitutional protections across the board. The Constitution refers to “invasion” in three other places: to describe appropriate domestic uses of the military; to set the standard for suspending the right to challenge unlawful imprisonments through habeas corpus; and to authorize the states to “engage in War” without the approval of the federal government. These are exceptional powers that must be wielded sparingly and responsibly, not in response to the political outrage du jour.
But Trump’s Guarantee Clause order doesn’t simply rely on an inapplicable clause of the Constitution. Asserting a novel, sweeping presidential authority in times of migrant “invasions,” the order states that individuals coming across the southern border “are restricted from invoking provisions of the [Immigration and Nationality Act] that would permit their continued presence in the United States,” including provisions of law that protect the right to seek asylum. Although Trump relies primarily (and erroneously) on a statutory provision for this directive, he also claims, in the alternative, a constitutional authority to unilaterally suspend congressionally enacted immigration law.
Even if an actual invasion were ongoing, Trump would not have that authority. In the foundational separation-of-powers case Youngstown Sheet & Tube Co. v. Sawyer, the Supreme Court established that the president, during wartime as well as peacetime, cannot bypass laws that Congress has constitutional authority to enact—regardless of whether the president also has constitutional authority in that area. The president may disregard statutory constraints only if Congress is trespassing on powers that the Constitution commits exclusively to the president. There is no question, however, that Congress has authority under the Constitution to enact immigration laws, including laws that allow undocumented individuals to seek asylum. The president accordingly must follow those laws.
Trump’s executive orders are unprecedented in many respects. Nonetheless, there are some lessons we can learn from history. This is not the first time that a president has falsely claimed an “invasion” across the southern border. In 1846, President James Polk proclaimed that Mexican forces had “passed the boundary of the United States” and “invaded our territory and shed American blood upon the American soil.” Within two days, he secured a congressional declaration of war.
Although Polk correctly identified the elements of an “invasion”—armed hostilities that require the government to meet force with force—he lied about the facts. Two years later, when the truth came out, then-Representative Abraham Lincoln charged that Polk had “unnecessarily and unconstitutionally” secured a war authorization through misrepresentation. Led by Lincoln, the House of Representatives passed language to censure Polk for unlawfully proclaiming an “invasion” to aggrandize presidential power.
What Lincoln and his fellow lawmakers did was brave; the Mexican-American War was still popular in 1848. But they understood that the U.S. system of government only works when the people can rely on the president to faithfully execute the laws.
Today, the country faces an even graver situation. The president has not only misrepresented the facts; he has misrepresented the Constitution itself. He has claimed unprecedented authority to ignore and override Congress whenever he proclaims an “invasion,” real or metaphorical. Congress should muster the courage required by these extraordinary times and condemn Trump’s radical attempts to usurp and abuse power.
(Editor’s note: This article is part of the Collection: Just Security’s Coverage of the Trump Administration’s Executive Actions.)