WASHINGTON -- Shortly before the Sept. 11 commission began public hearings a year ago, chairman Thomas Kean and Lee Hamilton, the vice chairman, made a deal: If a network asked one to be interviewed, he would demand the other be included.

"When they invite me, I say, no, not unless you want Lee Hamilton, too," said Kean, a Republican and former New Jersey governor referring to the former Indiana congressman, a Democrat. "We want to show the country this is a bipartisan effort."

Despite recent criticism that they have seemed partisan in questioning witnesses, the five Democrats and five Republicans on the commission investigating what led to the Sept. 11 attacks have remained remarkably and potently unified.

Acting with unanimity, the commission has repeatedly overpowered the White House and built its own stature in the process.

A unanimous commission forced testimony by National Security Adviser Condoleezza Rice and the release of a pre-9/11 intelligence memo to President George W. Bush about Osama bin Laden's interest in attacking the United States homeland. Before that, Bush and Vice President Dick Cheney agreed to meet with all 10 members, dropping their insistence on talking to just Kean and Hamilton. The private meeting is to occur soon.

And in February, the commission overcame White House opposition and won a 60-day extension. The commission now will complete a final report explaining what allowed the attacks to occur and recommending policy changes on July 26, the first day of the Democratic National Convention.

Quick review expected

The report cannot be released until the White House finishes its security clearance. But the timing, within months of Election Day, will probably achieve another commission goal: a speedy review by the White House eager to have a potentially damaging report made public as far from the election as possible and without accusations of delay.

"You've seen partisan moments in these hearings, but I'm really struck by the degree to which these people are working together," said Norman Ornstein, an analyst at the American Enterprise Institute in Washington.

Added a Senate Republican aide, "It's been quite extraordinary how much consensus there is on the commission."

The commission's cohesion has helped give credibility to a series of hard-hitting preliminary staff reports and must remain, commissioners say, if their final report is to gain any acceptance.

Even after an exhaustive congressional investigation into intelligence failures before Sept. 11, the commission has unearthed damaging new details and descriptions of systematic failures at the FBI and CIA.

One recent report said the FBI "never completed an assessment of the overall terrorist threat to the U.S. homeland." Intelligence agencies didn't document al-Qaida until 1999 -- 11 years after Osama bin Laden formed it -- and had "no complete authoritative portraits of his strategy ... or the scale of the threat his organization posed to the United States."

Another report revealed how the FBI waited until after Sept. 11 to show a photograph of terrorist suspect Zacarias Moussaoui to another detainee, who promptly recognized Moussaoui from al-Qaida training camps. In August 2001, CIA Director George Tenet received a report about Moussaoui titled "Islamic Extremist Learns to Fly" but took no action.

Moussaoui is charged with conspiracy in the attacks, and the commission said the Sept. 11 plot may have been stopped if his terrorist ties were known and authorities had been allowed to search his belongings.

Commissioner Tim Roemer, a former Indiana congressman who was on the congressional investigation in 2002, said the Sept. 11 commission has had "unbelievable access" to National Security Council documents, papers and e-mails that were denied its predecessor.

"We have been unified and nonpartisan insisting on it," he said. "It has absolutely been a night-and-day difference."

Kean, the commission chairman who last year criticized several agencies for withholding documents, said in an interview Thursday: "We've now gotten to some degree every single document we wanted. We've interviewed every single person we wanted. We're almost to the stage where we're ready to write the report."

Panel already having effect

The commission already is nudging Washington toward reform with its hearings' preliminary reports. Bush indicated last week a willingness to revamp intelligence agencies.

"Most blue-ribbon committees never hold public hearings of this sort," said Stephen Hess, a senior fellow at the Brookings Institution in Washington. "The decision of Kean to release these drafts in advance of the committee's ultimate report, from a public-relations sense, is quite remarkable."

Stephen Push of Virginia, a leading advocate for the commission whose first wife was on the plane that crashed into the Pentagon, said: "If you look back to right after Sept. 11, the position the FBI and CIA were taking was, we didn't do anything wrong. Now, when you have a carefully laid-out staff report backed up by a lot of information, you can't argue that there weren't things the FBI and CIA could have done better."

Tenet, the CIA director who was defiant testifying before congressional investigators in 2002, testified Wednesday, "We made mistakes" and proceeded to recite them.

Yet aggressive questioning and outspokenness have drawn criticism. Commissioners have spoken freely to the media and appeared on TV news shows, which Hess likened to "members of a jury coming out and discussing their opinions before they've reached a verdict."

Richard Ben-Veniste, a Democrat and an attorney, drew notoriety for sharply questioning Rice, the security adviser.

"The overwhelming majority of people in my district support the president and are turned off by the hearings," said Rep. Peter King (R-Seaford). "It turned into a partisan debate."

Other Republicans joined the criticism. House Judiciary Committee Chairman James Sensenbrenner of Wisconsin called for commissioner Jamie Gorelick to resign because she faced a conflict of interest while the commission looked into a memo she wrote as deputy attorney general in 1995 about information sharing by authorities.

On Friday, House Majority Leader Tom DeLay of Texas accused the commission of "partisan mudslinging, circus-atmosphere pyrotechnics, and gotcha-style questioning."

Kean, the commission chairman, said Gorelick would not deliberate on issues relating to her government work and brushed aside the conflict charge as "silly."

Commission members said they are determined to avoid criticism of partisanship by remaining united.

"We have a uniform understanding that the power of our report rests in part on the degree to which we can be unanimous in our findings and recommendations," Gorelick said. "People who do not agree with us or don't like the observations we make would try to dispatch our conclusions by saying we are partisan."