“I think it’s unconstitutional. I think we’d have to go to court," McCain said. | Getty McCain threatens court battle if Obama bypasses Congress on Guantanamo The dispute comes as the Pentagon prepares to release a report outlining options for closing Guantanamo.

Senate Armed Services Chairman John McCain is threatening a court battle if President Barack Obama tries to go around Congress in a last-ditch attempt to achieve his campaign pledge of closing the U.S. military prison at Guantanamo Bay, Cuba.

And the White House is doing little to squelch rumors that Obama might be preparing to do exactly that in order to remove what many have come to believe is a symbol of American overreach in confronting the terrorist threat, fueling militant recruiting.


Both sides are jockeying for leverage ahead of a possible constitutional showdown that could have a major impact on the legacy of a president nearing his final year in office.

The White House has suggested all options are on the table — leading the president’s GOP critics to believe Obama could be gearing up to use his authority as commander in chief to shutter the prison if lawmakers refuse to go along with a plan due out as soon as this week for clearing out the remaining 112 detainees.

It appears to be to the White House’s advantage to leave that possibility open. The prospect of Obama going around Congress could goad reluctant lawmakers into working with the president to come up with a legislative compromise for shuttering the military prison and transferring the inmates to the U.S. mainland.

But congressional Republicans are making clear they’re prepared to do whatever it takes to ensure the president defers to them on a divisive issue that raises big questions about the constitutional separation of powers.

“Rumors are that he will act again in an unconstitutional manner,” said McCain (R-Ariz.), a former prisoner of war in Vietnam who’s long stressed the need to close Guantanamo but wants the president to work with Congress to do so. “I think it’s unconstitutional. I think we’d have to go to court.”

The dispute comes as the Pentagon prepares to release a report outlining options for closing Guantanamo, which was established by President George W. Bush in early 2002 as U.S. forces began capturing suspected Al Qaeda operatives and leaders of the Taliban movement.

Many of the remaining detainees are slated to be sent to other countries, and some are facing military prosecutions. The big question, though, is what to do with the dozens of detainees the administration deems too dangerous to release — but lacks the evidence or will to prosecute.

The report is expected to lay out options for moving those detainees to federal or military prisons in the United States — an approach that would result in the closing of Guantanamo but wouldn’t end the indefinite detention that’s been decried by human-rights groups as extralegal and an affront to American values.

In preparing the report, defense officials visited facilities in at least three states — Kansas, South Carolina and Colorado — to assess their suitability, according to Pentagon spokesman Cmdr. Gary Ross, who stressed that the visits were “informational only.”

“The team of DoD officials is carrying out a review of military, federal and state-level civilian facilities that could be modified to securely and humanely hold detainees transferred from Guantanamo Bay,” Ross said.

But the plan is expected to be dead on arrival on Capitol Hill. Even the lawmakers who requested the report say they won’t support it if, as expected, it lists options for closing the prison rather than endorsing a specific path forward.

“If it has all these different options, it’s not a plan,” McCain said in an interview. “It’s passing the buck over to the Congress of the United States, knowing full well without a specific plan that it doesn’t have any chance — maybe laying the groundwork for what the president did on immigration, which is the executive order.”

At the White House, press secretary Josh Earnest said this week he would not take off the table the possibility the president could use executive authority to close Guantanamo. But, he emphasized, “the focus of our efforts right now is on Congress.”

And last week, two former administration officials published an op-ed in The Washington Post arguing the president does have authority to close the prison, despite congressional restrictions on doing so.

“The determination on where to hold detainees is a tactical judgment at the very core of the president’s role as commander in chief, equivalent to decisions on the disposition of troops and the use of equipment,” wrote former White House counsel Gregory Craig and Cliff Sloan, who was special envoy for Guantanamo closure in 2013 and 2014.

“Under Article II of the Constitution, the president has exclusive authority to determine the facilities in which military detainees are held,” they said. “Obama has the authority to move forward. He should use it.”

In response, congressional Republicans are making clear their view that the president can’t close the prison without their approval.

Over the past several years, Congress has passed a web of restrictions impeding the administration’s ability to shutter the facility, most notably a prohibition on using appropriated funds to transfer prisoners to the United States.

This year’s National Defense Authorization Act, passed with bipartisan support in the House and Senate and expected to be signed by the president, also bars funds from being used to modify U.S. facilities so that they could hold detainees.

In a statement, Senate Intelligence Chairman Richard Burr (R-N.C.) said the president “should listen to the will of the American people who have repeatedly rejected the president's plan to bring enemy combatants to the United States.”

In an interview Tuesday with Bloomberg TV’s “With All Due Respect,” new House Speaker Paul Ryan said Obama “doesn’t have the authority” to close the prison on his own.

"The law is the law," Ryan said. "It's just that clear."

But that may ultimately be up to a federal judge to decide if the White House and Congress can't come to agreement.

Some Republicans hope it won't come to that -- and that the forthcoming Pentagon closure plan will be a starting point for negotiations.

"We’ll see what they send up," Rep. Mac Thornberry (R-Texas), chairman of the House Armed Services Committee, said in an interview. "If it’s a serious plan, we will obviously have hearings and examine it and get opinions about it."

He added: "My bottom line is that if the administration can come up with a plan that can get some support [from] the American people and their representatives through Congress, then I don’t know of anybody who says Guantanamo has to stay open forever."

Jeremy Herb contributed to this report.