Democratic leaders in Illinois applauded a draft memo leaked to a conservative Web site Friday that they believe suggests the government is seriously considering transferring terrorist suspects from Guantanamo to their state.

The White House cautioned that the memo is merely a preparation in case such a decision is made, but Sen. Richard Durbin, D-Ill., and Gov. Pat Quinn said in a joint statement late Friday that it 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."

But one senior Republican lawmaker echoed other opponents of transferring detainees to the U.S., saying it would be "inexcusable."

"It's not an issue of how secure the prison is, it's an issue of giving terrorist enemy combatants access to the same rights as U.S. citizens," Rep. Lamar Smith of Texas, the top Republican on the House Judiciary Committee, said in a written statement late Friday. "There is no good reason to close Guantanamo Bay and no good purpose can be served by importing dangerous terrorists to the U.S. for detention and prosecution."

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The document was first posted on a conservative Web site known as Big Government, which described it as a Justice Department memo. Fox News later obtained a copy of the memo, which is addressed to the secretary of defense and is titled, "Directing Certain Actions with Respect to Acquisition and Use of Thomson Correctional Center."

A senior administration official said the document is one of many drafts written to cover various options for relocating Gitmo detainees, and no decision has been made.

"This is a draft, predecisional document that lawyers at various agencies were drafting in preparation for a potential future announcement about where to house Gitmo detainees," the official told Fox 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.

Before Obama can announce a final decision, he needs to sign an annual appropriations package, including a $1.1 trillion omnibus measure pending in the Senate, which details how the president will inform Congress about transferring detainees to U.S. soil for trial.

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. 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 Obama's old Senate seat in 2010, has asked elected officials to write 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.

Fox News' Mike Emanuel, Chad Pergram and The Associated Press contributed to this report.