When Presidents Overreach on Imprisonment

February 26, 2026

Can a President imprison people simply by invoking national security?

History — and the Supreme Court — answer that question more clearly than many assume.

The Constitution does not give the President unchecked authority to imprison individuals by executive decision. In fact, some of the Supreme Court’s most important rulings have drawn firm constitutional limits around that power.

After the Civil War, in Ex parte Milligan, the Court ruled that civilians could not be tried or imprisoned by military tribunals when civilian courts were open. Even in wartime, the President could not bypass ordinary judicial process.

During World War II, the Court reaffirmed that principle in Ex parte Mitsuye Endo, holding that the government lacked authority to detain a loyal American citizen without legal justification. The President could not imprison someone simply by executive command.

The Court did fail this principle in Korematsu, where it initially upheld the internment of Japanese Americans. That decision is now widely regarded as one of the Court’s gravest errors. Decades later, the Supreme Court formally repudiated Korematsu, and the Chief Justice publicly acknowledged that it was wrong.

These cases reflect a deeper constitutional safeguard: habeas corpus — the right to challenge unlawful detention. It was written into the Constitution precisely to prevent executive imprisonment without legal basis.

The lesson is not that the Court is infallible. It is that constitutional limits ultimately matter — and must be enforced.

Even in war. Even in crisis.

Liberty may be restricted only through law — never by presidential command.