One of Obama’s most prominent campaign pledges included a promise to close Guantanamo Bay. The prison camp has housed hundreds of prisoners in the war on terror since 2002, acting as a location to both detain and interrogate what the United States considers “extraordinarily dangerous people.”

Since it first opened though, the prison has come under increasing scrutiny. In addition to charges of torture, Amnesty International has called the facility the Gulag of our time, and the facility has drawn criticism from the international community and condemnation at the United Nations.

The criticism hit a fever pitch during the 2008 election and Obama promised he would close the facility. He followed that initial commitment by signing an order on his very first day in office to close the prison.

However, with just over a year left in office, that order has not been fulfilled. Over the past seven years, legal and political issues have prevented Guantanamo from closing.

First, Obama has encountered problems with where to send former detainees that are released. While Uruguay, Albania, and Saudi Arabia are a few countries that have taken in former prisoners who have been released, talks of other countries taking in people has largely stalled.

Obama also faces substantial opposition domestically to the possibility of transferring detainees to prisons on American soil.

Obama now faces heightened opposition from Congress, which passed a provision last week as part of a larger national defense spending bill that blocks the president from bringing any terrorist suspects currently in Guantanamo to the United States.

The bill passed by a vote of 91-3 in the U.S. Senate, marking widespread support for the spending commitments enumerated. The Guantanamo provision did not prevent many senators from signing on even though it was not the focus of the bill.

While various senators are in support of closing the facility, they are not happy with the possibility of transferring detainees to prisons in their states.

Particularly, a Pentagon report explored South Carolina, Colorado, and Kansas as possible locations with secure prison systems to send the remaining prisoners. But in a conference call, senators from those states stated that they were deeply upset at the possibility and would work to block these measures.

Obama has been frustrated at various measures where Congress has impeded his ability to act. As a result, he has frequently resorted to executive action to get his agenda through an intransigent Congress. The White House has already stated that they are not opposed to using executive action to close the prison camp.

Republicans in Congress have already stated that they will oppose any executive action that would close the prison or transfer detainees to the U.S., a fight that would carry over to the courts. Obama, therefore, faces a tough road to closing the prison while he is still in office, leaving the fate of the facility to the next president.

So far, the following candidates have declared their position on Guantanamo:

Hillary Clinton has stated her strong support for closing Guantanamo.

Martin O’Malley has stated that Guantanamo is one of ISIS’s biggest recruitment tools.

Bernie Sanders was one of the three no votes on the recent national defense spending bill.

Jeb Bush is against closing the facility.

Marco Rubio, Ted Cruz, and Rand Paul did not vote either way for the defense bill.

Ben Carson believes it is important to keep Guantanamo open.

John Kasich is against closing Guantanamo Bay.

Donald Trump has stated that he would detain American ISIS supporters in Guantanamo Bay.