Chief Justice Roberts argued that the Court should not have reached the Suspension Clause question before petitioners exhausted the DTA's review process. Congress had assigned the D.C. Circuit the task of deciding whether CSRT procedures complied with the Constitution and federal law, yet petitioners had not completed that review and the D.C. Circuit had not assessed its adequacy in a particular case.
He maintained that the Court prematurely invalidated a review system without deciding what substantive constitutional rights the detainees possessed. Habeas is a procedural mechanism, he reasoned, and there was no need to decide the writ's reach if the statutory system adequately protected every right detainees could claim.
Roberts read Hamdi as highly relevant. Hamdi held that a citizen challenging enemy-combatant detention was entitled to notice of the factual basis for classification and a fair chance to rebut it before a neutral decisionmaker, with procedures tailored to the burdens of ongoing conflict. In his view, CSRT proceedings followed by D.C. Circuit review supplied that basic process, and aliens could not demand more process than citizens.
He characterized the CSRTs as collateral review, not merely as the Executive's initial battlefield determination. The tribunals allowed detainees to testify, present evidence, call reasonably available witnesses, question Government witnesses, and obtain the assistance of a personal representative. The D.C. Circuit then could review compliance with the procedures and their consistency with the Constitution and laws.
Roberts contended that the DTA could be interpreted to permit meaningful remedies, including remand to a CSRT and release if required. He also believed the D.C. Circuit could remand for consideration of newly discovered exculpatory evidence, while Defense Department procedures separately allowed reconsideration based on new material evidence.
In his view, the majority replaced a carefully designed, congressionally enacted system with undefined habeas procedures to be developed later by district courts. That course would create uncertainty, duplicate review, and shift sensitive national-security judgments from the elected branches to the Judiciary.