Is the President's Indefinite Detention Power Limited to Foreigners?

Today (as Lucy Steigerwald noted) the Senate rejected an amendment to the 2012 defense authorization bill that would have removed a controversial provision authorizing indefinite military detention of terrorism suspects. Meanwhile, some conservatives are claiming there is no cause for alarm, a position to which National Journal lends credence by saying the provision "wouldn't apply to American citizens." Not so, says Rep. Justin Amash (R-Mich.), who calls it "one of the most anti-liberty pieces of legislation of our lifetime":

Although the bill says "the requirement to detain a person in military custody under this section does not extend to citizens of the United States," Amash said the language is "carefully crafted to mislead the public."

"Note that it does not preclude U.S. citizens from being detained indefinitely, without charge or trial, it simply makes such detention discretionary," he wrote.

Comments by supporters of the bill confirm that it applies to people arrested on U.S. soil, including American citizens. According to Sen. Lindsey Graham (R-S.C.), the bill will "basically say in law for the first time that the homeland is part of the battlefield" and that someone suspected of ties to Al Qaeda can be locked up without trial whether he is an "American citizen or not." (In September, Graham took a similarly broad view of the president's assassination powers, saying "restricting the definition of the battlefield" or "restricting the definition of the enemy" would be reckless because "this is a worldwide conflict without borders.") Sen. Kelly Ayotte (R-N.H.) likewise said the bill is necessary because "America is part of the battlefield." Defending the detention provision in The Washington Post yesterday, its co-authors, Sens. Carl Levin (D-Mich) and John McCain (R-Ariz.), did not claim the president's authority would be limited to foreign nationals or people captured in other countries. Responding to them in today's Washington Post, Sen. Mark Udall (D-Colo.), who sponsored the unsuccessful amendment aimed at removing the detention language from the bill, warns:

The provisions would require the military to dedicate a significant number of personnel to capturing and holding terrorism suspects — in some cases indefinitely — even those apprehended on U.S. soil. And they authorize the military to do so regardless of an accused terrorist's citizenship, even if he or she is an American captured in a U.S. city.

Last May the House approved its version of the defense authorization bill, which includes language defining the entire world as the battlefield in the war against Al Qaeda and requiring military detention of "foreign terrorists." President Obama has threatened to veto the bill if the final version includes restrictions on his discretion to treat terrorism suspects either as criminal defendants or as prisoners of war.

Update: Here is the roll call for the vote on Udall's amendment.