The Supreme Court has agreed to review a legal challenge to President Donald Trump's January 2025 executive order that bars virtually all legal migration across the southern border, a case that could determine whether the president may invoke the Constitution's guarantee of protection against 'invasion' to suspend migration indefinitely.
The Supreme Court granted review in Mullin v. RAICES. The Trump administration argues that illegal migration, drug smuggling and supposed 'public health' risks qualify as an 'invasion' under Article IV, Section 4 of the Constitution, which says the United States shall protect each state against invasion.
The district court and the D.C. Circuit ruled against the administration on statutory grounds without reaching the constitutional definition of 'invasion.' The Supreme Court could rule against Trump on those same grounds, but if it rejects the statutory arguments, or does so in large part, it will have to reach the broader constitutional question.
Ilya Somin, author of the article reporting the case, argues that the administration's position is 'badly wrong and has dangerous implications.' Somin writes that 'invasion' in the Constitution and in related statutes such as the Alien Enemies Act of 1798 must mean a military attack, not illegal migration or drug smuggling. He warns that a broad definition could let the federal government suspend habeas corpus and detain people, including US citizens, without due process, and could allow states to engage in war against neighboring countries without congressional approval.
Analysis
Why this matters
- The Supreme Court’s decision could redefine the constitutional meaning of 'invasion,' affecting the president’s power to act unilaterally on immigration and other national security matters.
- A broad ruling could threaten civil liberties, including habeas corpus protections for US citizens, according to legal scholars.
- The case is one of several major challenges to Trump administration immigration policies, alongside litigation over the Alien Enemies Act.
Background
President Trump issued the executive order in January 2025, citing the Guarantee Clause to justify suspending legal migration across the southern border. The order was immediately challenged by immigrant-rights groups, who won injunctions in lower courts. The Supreme Court’s decision to hear the case comes amid broader debates about executive authority and immigration enforcement.
Key perspectives
Trump administration: Claims that illegal migration, drug smuggling and public-health risks qualify as an 'invasion' under the Constitution, giving the president authority to suspend legal migration indefinitely.
Ilya Somin, legal scholar: Argues that 'invasion' must mean a military attack, not illegal migration or drug smuggling, and that a broad definition would have dangerous implications for civil liberties and federal power.
What to watch
- Whether the Supreme Court rules on statutory grounds or reaches the constitutional definition of 'invasion.'
- The reaction of Congress, particularly whether it moves to clarify the scope of the Guarantee Clause.
- Oral arguments, which could signal the justices' leanings on the scope of executive power.
Checked
11 claims in this story checked against 1 source: 10 supported.
Show each claim
- SupportedThe Supreme Court will review a challenge to Trump's “Invasion” executive order.Reason Magazine: “Yesterday, the Supreme Court decided to review Mullin v. RAICES, a case challenging the legality of Donald Trump's January 2025 "invasion" executive order”
- Partly supportedThe case tests whether the president can suspend legal migration by citing the Constitution's Guarantee Clause.Reason Magazine: “The Supreme Court could potentially rule against Trump on statutory grounds, without without reaching the issue of the definition of "invasion" in the Constitution. That is what the district court and the DC Circuit did.”
- SupportedThe January 2025 executive order bars virtually all legal migration across the southern border.Reason Magazine: “Donald Trump's January 2025 "invasion" executive order, which bars virtually all legal migration across the southern border.”
- SupportedThe case could determine whether the president may use the Constitution's protection against invasion to suspend migration indefinitely.Reason Magazine: “The administration claims that illegal migration, drug smuggling, and supposed "public health" risks qualify as an "invasion" under the Guarantee Clause, thereby authorizing the president to suspend legal migration indefinitely.”
- SupportedThe Supreme Court granted review in Mullin v. RAICES.Reason Magazine: “Yesterday, the Supreme Court decided to review Mullin v. RAICES”
- SupportedThe Trump administration argues that illegal migration, drug smuggling and supposed public-health risks qualify as an invasion under Article IV, Section 4.Reason Magazine: “The administration claims that illegal migration, drug smuggling, and supposed "public health" risks qualify as an "invasion" under the Guarantee Clause”
- SupportedThe district court and D.C. Circuit ruled against the administration on statutory grounds without deciding the constitutional meaning of invasion.Reason Magazine: “The Supreme Court could potentially rule against Trump on statutory grounds, without without reaching the issue of the definition of "invasion" in the Constitution. That is what the district court and the DC Circuit did.”
- SupportedThe Supreme Court may have to reach the constitutional question if it rejects the statutory arguments, or rejects them in large part.Reason Magazine: “But if it rejects these statutory arguments, or at least does so in large part, it will have to reach the "invasion" issue.”
- SupportedIlya Somin calls the administration's position “badly wrong and has dangerous implications.”Reason Magazine: “The Trump administration's position on this issue is badly wrong, and has dangerous implications.”
- SupportedSomin argues that invasion in the Constitution and the Alien Enemies Act must mean a military attack, not illegal migration or drug smuggling.Reason Magazine: “"invasion" - as that term is used in the Constitution and the AEA - must be a military attack, not illegal migration, drug smuggling, or other similar activity.”
- SupportedSomin warns that a broad definition could enable the federal government to suspend habeas corpus and detain people, including US citizens, without due process, and enable states to wage war against neighboring countries without congressional approval.Reason Magazine: “it would allow the federal government to suspend the writ of habeas corpus (and thereby detain people - including US citizens - without due process) at any time. It would also give state governments the power to "engage in war" against neighboring foreign countries at virtually any time, even without congressional authorization.”