We have long since made clear that a state of war is not a blank check for the President when it comes to the rights of the Nation’s citizens.

Sandra Day O’Connor wrote this line as the author of the U.S. Supreme Court’s majority opinion in Hamdi v. Rumsfeld (2004), a post‑9/11 case challenging the executive branch’s power to detain a U.S. citizen as an “enemy combatant” without meaningful judicial process. The Court held that although Congress’s Authorization for Use of Military Force permitted detention of combatants captured in Afghanistan, due process still required that a citizen-detainee receive notice of the factual basis for detention and a fair opportunity to rebut the government’s assertions before a neutral decisionmaker. The statement situates wartime authority within constitutional limits and judicial oversight.

The quote rejects the idea that war automatically expands presidential power to the point that individual rights can be suspended at will. O’Connor frames constitutional liberties as constraints that persist even under emergency conditions: the executive may act decisively, but not without legal authorization and procedural safeguards. The “blank check” metaphor underscores the Court’s role in preventing indefinite, unreviewable detention and in insisting that national security measures remain accountable to law. More broadly, it articulates a central separation‑of‑powers principle: wartime does not erase the judiciary’s duty to enforce due process for citizens.