Now a newspaper report says Obama's plans have hit a new hurdle -- it may be too expensive to close.
The Wall Street Journal reports the White House rejected a Pentagon plan to close Gitmo and build a new U.S. prison in its place, because the cost estimates were too high.
The price tag would have been around $600 million -- reported the Journal, citing administration officials -- so the plan was sent back to the Pentagon for revisions.
It's just the latest in a series of years-long setbacks to closing the military prison, one of Obama's most-repeated campaign promises during his 2008 run and one of the first executive orders he signed when he took office in January 2009.
Obama says the prison -- which holds suspected members of terrorist groups captured overseas -- is a recruiting tool for terrorists and is too costly to maintain. He's whittled down the number of detainees from 241 to 107 during his time at the White House, and he said last month he expected that number to get below 100 by early next year. But he has hit roadblock after roadblock -- most often placed by Capitol Hill -- in his effort to clear out the prison.
In 2009, an effort to transfer 17 Uighur detainees -- members of a Chinese Muslim minority deemed no threat to the United States -- to northern Virginia collapsed after the region's lawmakers revolted.
In May of that year, the Democrat-controlled Senate voted overwhelmingly against allowing government funds to close Guantanamo. An administration plan to move detainees to a supermax prison 150 miles south of Chicago met a similar fate in Congress.
In balking at the transfers, Republican and Democrat lawmakers alike repeatedly cited security fears expressed by their constituents about housing suspected terrorists near their families.
Legislators later banned the administration from transferring any detainees into the United States in a war spending bill that Obama aides deemed too important to veto.
Amid the setbacks, Obama forged ahead with a plan to bring detainees into the United States for trial. The administration announced in November 2009 that five prisoners accused of plotting the September 11 attacks would be tried in New York City.
The administration said the move would demonstrate the country's commitment to rule of law. But fierce political opposition got in the way. New York officials objected to what they said were the enormous costs of securing the downtown Manhattan courthouse, and some family members of 9/11 victims said holding the trial so close to ground zero would open painful wounds.
The United States instead tried the detainees within the military system at Guantanamo -- a process that is still slogging along, beset by challenges from the defense and likely still years away from a resolution.
The issue faded into the background during the rest of Obama's first term, only to roar back to life at the start of his second when a number of detainees went on hunger strikes. The transfer of detainees to other countries increased, but the hang-up over moving detainees to the United States remains. White House officials say there will ultimately be a number of prisoners who can't be transferred because they're deemed too dangerous or their home countries are unstable.
And Congress continues to resist any option that involves moving detainees into the United States.
The report from the Journal said Obama asked the Pentagon to reduce the plan's price tag by paring down the costs of a proposed new military prison in the United States.
During the summer Obama told Congress he was close to delivering what will probably be his last Guantanamo closure plan, but so far nothing has been given to lawmakers to review.