Fending off criticism from human-rights and civil-rights groups at a private White House meeting Wednesday, a frustrated President Obama complained about the "mess" he'd been left by his predecessor.

The exchange came during an hour-and-15-minute "off the record" session in the White House cabinet room that highlighted growing tensions between the president and his liberal base. While the White House session was billed as an effort by the president to listen to his critics on the left, some of them left disappointed. 

According to three sources who attended the meeting, Obama reiterated his intention to retain a version of the military-tribunal system established to try terror detainees and said his administration will likely end up adopting some form of "indefinite detention" policy to justify holding some selected suspects without trial.  Still, Obama brusquely rejected suggestions by some of those present that, in doing so, he was adopting key tenets of Bush-era policies considered unacceptable by his liberal supporters.

"It doesn't help to equate me to Bush," Obama said, arguing that such comparisons overlook important differences between the two administrations' policies, according to several sources attending the meeting.

The sources, all of whom asked not to be identified because of the White House insistence that the meeting was private, also said Attorney General Eric Holder sat by silently while the president curtly dismissed the idea that his Justice Department should criminally prosecute at least one Bush administration official for torture, if only as a symbolic move to demonstrate that actions such as waterboarding will never be tolerated again.

While declining to talk about any of the specific back-and-forth, American Civil Liberties Union executive director Anthony Romero told NEWSWEEK he was not happy about much of what he heard during the meeting. Obama showed a "remarkable command" of the issues, Romero said. But, he added,  "it is disappointing that he appears poised to continue with many of the Bush policies that have ended in failure. If he goes down that track, President Obama will find himself in the same legal morass that swallowed up George Bush."

The session was held even as the Senate was voting by an overwhelming margin to reject the administration's request for funds necessary to shut down Guantánamo. The vote was a stunning setback for the president, potentially undermining his vow to shut down the detention facility by the end of the year. The messy split between the White House and Congress sparked complaints among some Democrats that the administration had mishandled the issue, ceding ground to Republican critics like former vice president Dick Cheney.  "The Republicans smell blood in the water on this," said one Democratic Senate aide.

Obama will seek to regain control of the debate with a major speech at the National Archives Thursday, in which aides say he will lay out a broad vision for overhauling Bush-era counterterrorism policies while still protecting national security. But the speech is expected to provide few details about how precisely the president plans to proceed with closing Guantánamo or deal with the more than 240 detainees still at the facility, according to sources familiar with the address.

While the criticism from Cheney and other Republicans has been a constant in the Washington media, Wednesday's meeting underscores how worried the White House is about critics closer to home. Administration officials organized the session just a few days ago, summoning the leaders of groups such as Human Rights Watch, Human Rights First, the Center for Constitutional Rights and the ACLU, as well as several liberal law professors. As a sign of how seriously the White House took the matter, just about all of Obama's senior staff were there, including chief of staff Rahm Emanuel, White House counsel Gregory Craig, senior adviser David Axelrod and Holder.