But for Democrats, the latest developments have only given them a renewed reason to push for sworn testimony, as they pointed to the inaccurate or misleading statements made by the Justice Department or the White House on the firings, a list of which they said seemed to grow every few days.

Justice Department officials first said the White House approved the ouster plan only after it was initiated by Justice, but e-mail messages have shown that officials at the White House initiated the effort, shortly after the 2004 elections.

Justice Department officials at first gave no reasons for the firings, then cited performance problems with the prosecutors, and, finally, acknowledged that performance could not be cited in each of the cases as the rationale for the firings.

Officials have said that politics played no role in the firings. But they later acknowledged that they had received repeated telephone calls from one Republican senator who sought the ouster of the New Mexico prosecutor, and that a second United States attorney, in Arkansas, was dismissed to make room for a former aide to Mr. Rove.

Stanley M. Brand, a lawyer in Washington and former Democratic counsel to the House, said the United States attorney matter was turning into a classic Washington saga, where statements made by public officials after the fact are as damaging as any role they may have played in the actual events.

“That is the classic conundrum that people get into, they obfuscate, or don’t tell the whole story, and that itself is what becomes the legal controversy,” Mr. Brand said. “The shifting story of what is at the bottom of these decisions on the United States attorneys is the primary reason that Congress keeps grinding away. That is always the fuel for these investigations.”

As attorney general, Mr. Gonzales has become a central figure, and increasingly, critics say, the emblem of ineptitude, in the swirl of contradictions, memory lapses and conflicting testimony that has defined the unfolding story behind the removal of the prosecutors.