After threatening a veto, President Obama signed a defense bill that places restrictions on his ability to transfer prisoners out of Guantanamo Bay. However, he attached a signing statement that claims he has the power under the Constitution to override the limits set by Congress in the bill, which funds the Defense Department for the next year.

Obama vowed to close the military prison upon taking office in 2009, but Congress made sure the prison remained open by placing limits on the transfer of terror suspects to the U.S. or to other nations.

On America's Newsroom this morning, Patti Ann Browne sat down with Judge Andrew Napolitano to discuss the action and the use of signing statements in general.

Napolitano explained that the signing statement - "a piece of paper on which the president puts his objections about the law as he signs it into law" - has been used by every administration since Ronald Reagan, and that George W. Bush used signing statements 1,200 times.

Regardless of what Congress does though, the judge believes President Obama could, if he chooses, shut down Guantanamo Bay whenever he wants and transfer the detainees elsewhere. The reason is that the president, as commander of the armed forces, has the power to choose where military prisoners are housed, and as "the chief law enforcer" he can decide where the Justice Department houses civilian prisoners.

"Can the courts undo that? They probably wouldn't touch it with a ten-foot pole and they would say 'it's a political dispute between the White House and the Congress, let them resolve it,'" Napolitano said.

Napolitano added that Congress cannot pass a law that limits powers granted to the president in the Constitution.

The judge then pointed out another provision in the defense bill that he believes would be "invalidated" by the courts if it is ever challenged.

"There's also a provision in this law that lets the military arrest people, Americans in America, and hold them without bringing them to a judge or a jury or without filing charges against them. There are members of Congress who opposed that but they voted in favor of the law because they didn't want to shut down the Defense Department," he said.

Watch the full discussion: