There was no shortage of outrage at Wednesday’s Senate hearing on closing the detention facility at Guantánamo Bay. Both critics and supporters of the prison repeated well-rehearsed arguments about why keeping it open—or shutting it down—would harm national security and American interests more broadly. Sen. Dick Durbin (D-IL), who chaired the Judiciary Committee panel, argued that “every day it remains open, Guantánamo prison weakens our alliances, inspires our enemies, and calls into question our commitment to human rights.” Sen. Ted Cruz (R-TX) countered that shuttering the facility would endanger the lives of Americans. “Until we are presented with a good, viable strategy for what to do with terrorists who would work night and day to murder innocent Americans,” Cruz said, “I have a hard time seeing how it is responsible to shut down our detention facilities and send these individuals home, where they would almost surely be released and almost surely would return to threaten and kill more Americans.”

Over the course of the nearly two-hour hearing, the first held in the Senate in five years, senators and witnesses raised plenty of other well-worn arguments. Guantánamo critics pointed to the high cost of keeping detainees incarcerated at the facility—$2.7 million a year per detainee. A former Bush administration Defense Department official argued that transferring them to U.S. prisons would allow them to spread their brand of “radical Sharia,” or Islamic law, to the homeland.

What the hearing did not address—at all—were the practical steps that could be taken to follow through on President Obama’s renewed promise to shutter Guantánamo. And it was notable that no member of the Obama administration, which is largely responsible for developing a plan of action, testified at the hearing. (A Durbin aide said the administration was invited but declined to send a witness.)

Maintaining a low profile for the moment likely reflects a desire to duck some tough questions. Chief among them is whether the administration plans to use its existing authority to start transferring detainees out of Guantánamo. Of the 166 prisoners who remain in the camp, 86 have been cleared for release. And while Congress repeatedly has imposed onerous restrictions on repatriating or moving detainees to third countries, more recently it has provided waivers for the administration to bypass those limitations. Originally Congress required certification from the secretary of Defense that prisoners transferred out of Guantánamo would not engage in any future terrorist activity, an almost impossible standard to meet. Now that requirement can be waived so long as the receiving country can “substantially mitigate” the risk that the detainee will return to terrorism, a lower threshold.

The administration so far has not invoked its waiver authority to transfer detainees. But in the wake of Obama’s revived initiative to close Guantánamo, opponents of keeping the facility open have urged the administration to do so. In a new report, “Guantanamo: A Comprehensive Exit Strategy,” Human Rights First calls on the administration to “certify transfers and issue national-security waivers to the fullest extent possible.” And there were signs that at least some in the administration were listening. Officials at the State Department and Justice Department are said to be in favor of a plan to begin transferring a small number of detainees using national-security waivers. To start, it would likely involve detainees from countries, including Morocco and Algeria, that have demonstrated an ability to safely integrate terror detainees. In reality, it would take the White House to direct the secretary of Defense to issue the waivers and begin the transfers.

But sources tell The Daily Beast that the White House remains opposed to the plan. Officials say the requirement that the receiving country substantially mitigate the risk of released prisoners returning to terrorism is still too high a burden to meet. That was the message last week, when Sens. Durbin and Dianne Feinstein (D-CA) met with Lisa Monaco, President Obama’s chief counterterrorism adviser, and Kathryn Ruemmler, the White House counsel, in Durbin’s Capitol office. Two sources familiar with the meeting say Monaco and Rummler raised serious concerns about using the waivers to transfer detainees.

Durbin alluded to the meeting with Monaco and Ruemmler at the hearing Wednesday and hinted that the White House was not ready to use all of its existing authority close Guantánamo. “I’ll be the first to acknowledge that the administration could be doing more to close Guantánamo,” Durbin said, before telling the hearing’s attendees that he and Feinstein had met with “senior White House officials to discuss what they are doing under existing law to transfer detainees out of Guantánamo.”

The White House’s reticence to use its waiver authority raises questions in the minds of Guantánamo opponents about how committed the administration is to shutting down the prison. “The president has been clear that he wants Guantánamo closed, and the national-security waiver provides an avenue to start clearing transfers,” said C. Dixon Osburn, director of Human Rights First’s law and security program. “If the White House believes it does not have the authority, they should tell Congress what authority they need and make it to the Hill and say so.”

In a way, that’s what the White House is already doing. The administration is strongly backing new legislation, passed by the Senate Armed Services Committee, that would lift many of the restrictions that have effectively banned the transfer of Gitmo detainees to other countries or to the U.S. homeland. But the legislation still has to pass the full Senate and the House, which right now looks like a steep climb.