Trump blocked from migrant deportations under 18th-century law as Supreme Court intervenes

US Supreme Court blocks Trump-era migrant expulsions under Alien Enemies Act

The United States Supreme Court has temporarily halted the Trump administration’s deportation of Venezuelan migrants under the Alien Enemies Act, a rarely used law from the 18th century. The emergency order, issued on April 19, comes in response to legal challenges arguing that the administration failed to uphold constitutional due process protections.

The case marks a major judicial check on the administration’s immigration enforcement strategy, particularly its controversial use of wartime-era legislation to remove migrants who had not been granted adequate opportunity to challenge their deportation. The order followed a petition from the American Civil Liberties Union (ACLU), which claimed the government had violated prior Supreme Court precedent by bypassing legal safeguards.

What is the Alien Enemies Act and why is it in focus now?

The Alien Enemies Act, enacted in 1798 as part of the Alien and Sedition Acts, gives the U.S. president power to detain or deport nationals of countries deemed hostile during wartime or national emergency. While used during World War II, the law has seen little invocation in recent decades.

In March 2025, President Donald Trump invoked the statute by declaring that the Venezuelan criminal group Tren de Aragua constituted an organized threat, describing their movement across the U.S. southern border as a form of “invasion.” Relying on this justification, over 130 Venezuelan migrants were apprehended and summarily deported to El Salvador — a third country not their country of origin — where they were confined at the high-security Terrorism Confinement Center (CECOT).

Critics, however, argue that invoking a wartime law in peacetime without congressional approval or a formal declaration of war stretches the executive’s authority beyond constitutional bounds.

Supreme Court intervenes over due process concerns

The ACLU challenged the deportations on the basis that the individuals affected had not received proper notice or legal counsel before removal — violating core due process requirements. The Supreme Court’s emergency stay prevents further deportations under the Alien Enemies Act until the matter is fully litigated.

The order, which was unsigned, garnered majority support from the Court’s liberal wing along with some conservative justices. Justices Clarence Thomas and Samuel Alito dissented, expressing concern about limiting presidential authority during national security-related actions.

While the decision does not represent a final ruling on the constitutionality of the deportations, it halts enforcement of the policy for now, ensuring that pending removals will be subject to judicial oversight.

Legal and political implications for immigration enforcement

The Court’s decision raises critical questions about the Trump administration’s broader use of executive power in immigration matters. By invoking a centuries-old statute in a modern migration context, the administration’s policy risks clashing with constitutional guarantees for non-citizens — including the right to a fair hearing and protection from arbitrary detention.

Human rights advocates and legal analysts argue that the deportation of migrants to high-security prisons in third countries, without individual assessments or asylum screenings, undermines both U.S. legal norms and international refugee conventions.

The ruling also reflects a broader judicial pattern of skepticism toward executive actions that cite national security as justification for bypassing standard legal processes. Previous court interventions have blocked Trump-era policies ranging from family separation to asylum restrictions and expedited removals.

Trump’s second-term immigration push faces judicial roadblocks

The Supreme Court’s intervention comes as the Trump administration intensifies immigration enforcement efforts early in the president’s second term. The decision to invoke the Alien Enemies Act — a statute that has remained largely dormant — is viewed by some political analysts as part of a wider strategy to project a tough stance on border security ahead of a possible 2026 midterm referendum on Trump’s agenda.

However, this legal setback adds to a growing list of challenges from civil rights organizations and federal courts. These cases are likely to define the boundaries of presidential power on immigration for years to come.

Judicial sentiment signals limits on executive authority

While the Supreme Court has not issued a final ruling, its emergency stay halts further removals until the case is litigated in full. Legal analysts suggest that unless the Trump administration can provide compelling national security justification and show compliance with constitutional standards, the Court may impose significant constraints on the policy’s continuation.

The Court’s action underscores the principle that constitutional protections — including due process and access to legal recourse — must apply to all individuals within U.S. jurisdiction, regardless of citizenship or immigration status.

As the legal battle unfolds, the ruling represents a critical test of how far executive authority can be extended in the name of national security — and whether 18th-century legal frameworks remain fit for the complexities of 21st-century migration and asylum policy.