Supreme Court endorses indefinite detention without a hearing in Shaughnessy v. Mezei

The Supreme Court ruled 5-4 in Shaughnessy v. United States ex rel. Mezei that the federal government could indefinitely detain a long-term U.S. resident at Ellis Island without a hearing, relying on the plenary power doctrine to hold that whatever process Congress authorizes constitutes sufficient due process for noncitizens. Ignatz Mezei had lived in the United States for 25 years; upon returning from Hungary, the Attorney General ordered his exclusion on undisclosed national security grounds with no opportunity to contest the evidence. Justices Black and Douglas dissented, warning that the ruling allowed government to imprison people without judicial accountability.