Sen. Majority Whip Dick Durbin, D-Ill., and Sen. Patrick Leahy, D-Vt., wrote a letter along with 22 other Democrats to President Biden asking him to shut down the military prison in Guantanamo Bay.
The lawmakers said closing the prison that was established to detain suspected terrorists after 9/11 was a "critical step" in Biden’s pledge to "put universal rights and strengthening democracy at the center of our efforts to meet the challenges of the 21st century."
"As a symbol of lawlessness and human rights abuses, the detention facility continues to harm U.S. national security by serving as a propaganda tool for America’s enemies and continues to hinder counterterrorism efforts and cooperation with allies," the senators wrote.
The White House said in February Biden would seek to shut the prison after a review process, resuming a project begun under the Obama administration. Obama had pledged to shut the prison within a year of taking office. The Biden White House did not offer a timeline.
Obama ran into intense Congressional opposition when he sought to close the detention center, a notorious symbol of the U.S. fight against terrorism. Biden may have more leeway now that there are only 40 prisoners left and Guantanamo draws much less public attention, though his announcement did spark some criticism.
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"The Democrats’ obsession with bringing terrorists into Americans’ backyards is bizarre, misguided, and dangerous," Sen. John Cornyn, R-Texas, said after Biden made the announcement. Cornyn said Republicans would fight Guantanamo's closing "tooth and nail," just as they did under Obama.
Defense Secretary Lloyd Austin said in his Senate confirmation he supported shuttering the prison’s doors as well.
At its peak in 2003, the detention center at the Navy base on the southeast tip of Cuba held nearly 680 prisoners. Amid the international outrage, President George W. Bush called it "a propaganda tool for our enemies and a distraction for our allies" and said he supported closing it but left it to his successor.
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It's not exactly clear how much the federal government spends housing its Gitmo prisoners, but it's somewhere between $9.5 and $13 million per prisoner, per year.
Obama cited cost-cutting as another reason to shut the facility. Under his administration, 197 were repatriated or resettled in other countries.
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That left 41 under Trump, who pledged at one point to "load it up" with some "bad dudes." But upon learning of the estimated cost of detaining the prisoners, Trump said, "I think it’s crazy." He did not add any prisoners to the island and approved one release.
Of those who remain at Guantanamo, 10 men are waiting for trial by military commission, five of whom are charged with planning and providing logistical support to the Sept. 11, 2001, terrorist attacks. The case has been bogged down in pre-trial proceedings for years.
The Associated Press contributed to this report.