Attorneys for Senators John McCain, Lindsey Graham, and Kelly Ayotte---all members of the Senate Committee on Armed Services---have filed an amicus brief in support of the government in Hedges v. Obama. (Background here.)
From the brief's "Introduction and Summary of Argument" section:
Because “detention to prevent a combatant's return to the battlefield is a fundamental incident of waging war,” Congress anticipated that the President would, pursuant to the Authorization for the Use of Military Force (“AUMF”), detain enemies not killed on this war’s battlefields. Hamdi v. Rumsfeld, 542 U.S. 507, 519 (2004). President Bush and President Obama have done so. Their administrations have used this authority to remove and keep from the battlefield numerous individuals, most in Afghanistan, who joined with al-Qaeda in waging war against the United States and its allies, to obtain valuable intelligence, and, where appropriate, to bring these individuals to justice through prosecution. The contours of this authority were developed by the executive branch over time, on a case-by-case basis, according to military necessity and subject to regular oversight by Congress and, when appropriate,
the courts. That process culminated in the Obama Administration’s March 2009 Memorandum setting forth the detention authority that had been exercised by the executive branch to that point and Congress’s ratification of that authority in Section 1021 of the National Defense Authorization Act for Fiscal Year 2012 (“NDAA”).
The plaintiffs, and the court below, ignore this history and, as a
result, misconstrue Congress’s purpose in enacting Section 1021. Far from seeking to authorize the detention of individuals for engaging in political activism or practicing journalism—something that Congress, in general, and amici, in particular, reject—Congress sought to endorse the specific detention authority that had been exercised by the executive and approved by the courts and thereby place it on the strongest possible constitutional footing, consistent with Youngstown Sheet & Tube Co. v. Sawyer, 343 U.S. 579, 635-37 (1952) (Jackson, J., concurring). And Congress did so in the plainest possible terms, expressly stating that “[n]othing in this section is intended to limit or expand the authority of the President or the scope of the Authorization for Use of Military Force” or to affect the rights of persons captured within the United States, including the right to challenge detention before a court
of competent jurisdiction. NDAA §§ 1021(d), (e). But the court below refused to take Congress at its word. In so doing, it stymied Congress’s exercise of its powers to declare war and authorize the use of force, to make rules concerning captures, and to regulate the armed forces.
Section 1021 is unquestionably a legitimate exercise of those powers. It is informed by the customary laws of war—including the detention of captured enemy personnel for the duration of hostilities and the law of co-belligerency—applying them to a type of conflict that involves shadowy non-state actors with fluid affiliations, rather than the uniformed soldiers of nation-states. Moreover, authorizations for exercise of the war power—as opposed to the exercise of that power in specific circumstances—have never been subject to review for vagueness because they structure the operations of the government and, unlike statutes creating criminal offenses, do not work directly on individuals or impair individuals’ rights. Nor, for the same reasons, are such structuring statutes subject to facial challenge for violation of First Amendment rights. In these ways, the decision below is inconsistent with centuries of constitutional practice in authorizing the use of military force. The plaintiffs may not circumvent precedent barring challenges to the authorization and use of military force by seeking to enjoin an essential aspect of that force.