In a joint statement, Durbin, D-Ill., and Gov. Pat Quinn said the memo signals "the administration has narrowed its focus" to a nearly empty maximum-security state prison in Thomson, a sleepy town of 450 people near the Mississippi River about 150 miles west of Chicago.
"Even though the final decision has not been made, we are encouraged by this development," Durbin and Quinn said. "We will continue working with the White House, the Defense Department and the Justice Department to address important questions regarding security and job creation, and finalize this agreement."
The document was posted on a conservative Web site known as Big Government, which described it as a Justice Department memo.
A White House official described the memo as a "pre-decisional," stressing that a final decision has not been made. The official was not authorized to discuss the document and would speak only on condition of anonymity.
"This is a draft, pre-decisional document that lawyers at various agencies were drafting in preparation for a potential future announcement about where to house GTMO detainees," the official told CBS News. "Drafts of official documents are often prepared for any and all possibilities, regardless of whether a decision has been made about the policy or if the document will be used."
A source tells CBS News that there are a number of locations still on the table and drafts are being prepared for each one. At this point, Illinois has not been chosen as the new home for the detainees.
The Thomson Correctional Center was one of several potential sites evaluated by the Federal Bureau of Prisons but has emerged as a leading option to house detainees held at Navy-run prison in Guantanamo Bay, Cuba.
Closing the facility is a top priority for President Obama. He has said he wants terrorism suspects transferred to American soil so they can be tried for their suspected crimes.
The Thomson Correctional Center was built by Illinois in 2001, with designs on improving the local economy. State budget problems have kept the 1,600-cell prison from fully opening. At present, it houses about 200 minimum-security inmates.
It's not clear how many detainees from Guantanamo would be transferred or when. Mr. Obama had originally set a closing date for the Guantanamo Bay prison on Jan. 22, but the administration has acknowledged that deadline is no longer likely to be met.
If the facility is chosen, it would likely be purchased by the Federal Bureau of Prisons and run primarily as a standard federal prison. However, a portion of the facility would be leased to the Defense Department to house a limited number of Guantanamo detainees.
Many local officials, as well as Durbin and Quinn, have cheered on news that the Thomson facility may be selected. But some lawmakers have also voiced opposition to the idea that terrorism suspects would be brought to Illinois.
Earlier this year, Rep. Mark Kirk, a suburban Chicago Republican seeking Mr. Obama's old Senate seat in 2010, has asked elected officials to write Mr. Obama opposing a plan that would bring terrorism suspects to Illinois. Kirk has said that doing so would make the prison and the state targets for terrorist attacks.
Thomson is not the only U.S. town that had hoped to lure Guantanamo detainees. Officials in Marion, Ill., Hardin, Mont., and Florence, Colo., also have said they would welcome the jobs that would be generated.
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