Sloan has been holding meetings across Capitol Hill to push for more flexibility, while Lisa Monaco, Obama's top counterterrorism adviser in the White House, has been calling moderate senators to encourage them to back the Senate bill.
The bill would allow the Pentagon to transfer any detainee the administration no longer considers a threat to the United States, as long as actions are taken to "substantially mitigate the risk" that the detainee would re-engage in terrorism and ensure that the transfer is in the U.S. national security interest.
The U.S. Conference of Catholic Bishops weighed in Monday in support of the Senate bill as keeping with tenets of their faith for swift justice and against torture. The group urged senators in a letter to back the looser restrictions on transfers to "help the United States regain its moral standing in the world as a defender of human rights."
This summer, the administration sent home two Algerian detainees. Eighty-four others have long been cleared for transfer, and the U.S. government has begun a formal review process of about 45 others previously considered too dangerous to be released to determine if circumstances have changed.
Ayotte argued the Algerian transfers prove the current process is working, and Sen. John McCain, R-Ariz., agreed that the administration doesn't need more flexibility. "All they have to do is assure us that they won't re-enter the fight, as numerous ones have, in leadership positions. We can't do that," McCain said.
Chris Anders, senior legislative counsel for the American Civil Liberties Union, which wants to close Guantanamo, acknowledges the issue is always a tough vote for lawmakers. But he argues there's a growing recognition that Guantanamo can't stay open forever and harms national security.
"What's different this year compared to past years is that the president is ready and willing to use whatever authority Congress gives him to start closing Guantanamo," Anders said, "and particularly to start sending home the majority of detainees who were long ago cleared to be sent back home."
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