The Senate voted 93-7 to permit indefinite detention without trial even of U.S. citizens arrested within the U.S.
"President Barack Obama has outlined plans to use indefinite detention and lawmakers in both parties sought to make clear such a tactic is legal."
Also, "Some Republicans aligned with the tea party movement, led by Kentucky Sen. Rand Paul, have railed against provisions that Mr. Paul argued violated the Constitution, aligning himself with liberal Democrats." I kind of thought tea party Republicans and liberal Democrats would have added up to more than 7 votes in the Senate. Too bad they couldn't rally another 34 votes.
I haven't found any single article that presents it all clearly, but piecing it together from various sources, I think the issue is that right now, the executive branch has a very free hand in how it wants to handle indefinite detentions, as it's only constrained by a rather vague opinion in Hamdi v. Rumsfeld. In particular, prisoners can be turned over to FBI detention rather than held by the military. My understanding is that this legislation only permits indefinite detention as a prisoner of war by the military, unless the secretary of defense formally issues a waiver. That "red tape" is what the Obama administration objects to, as Obama trusts the loyalty of the FBI more than he trusts the military.
Edit: there's a description of the specific provisions of the bill here:
The sponsors, Senators Levin (D) and McCain (R), discuss the provisions here:
Edited at 2011-12-03 07:29 am (UTC)
And a good general overview with lots of links here:
This article also specifically discusses the Obama administration's objections to the bill, and links to the following from a former Obama supporter, who notes that it was the Obama administration that asked for removal of language that would at least have exempted American citizens and lawful residents: