At a House Judiciary Committee hearing, Rep. Jim Sensenbrenner of Wisconsin said impeachment is an option if Holder does not "clean up this mess" quickly.
Sensenbrenner and other Republicans hold the attorney general responsible for the operation, in which federal agents failed to track illicitly purchased weapons that were later recovered in Mexico and the U.S., many of them at crime scenes.
"If you don't get to the bottom of this," there is only one alternative, and "it's called impeachment," said Sensenbrenner, without specifying whom he had in mind.
"Why haven't you terminated the people involved?" asked Rep. Darrell Issa, R-Calif., who chairs the House Oversight and Government Reform Committee that is investigating the arms-tracking operation. Issa pressed Holder to appear before the congressman's committee, and the attorney general said he would consider the request.
Issa told Holder that the Justice Department has turned over 5,000 emails to the committee about Operation Fast and Furious, but "not one of these emails is yours." The attorney general said that his department's response to the committee's document requests has been "fulsome" and that the Justice Department would not turn over additional emails sought by Issa. The California congressman said he wants emails from March of this year between a Holder aide and Justice Department criminal division head Lanny Breuer. Issa suggested Holder could be cited for contempt of Congress if the material is not provided.
The attorney general, the sole witness at Thursday's hearing, said it was inexcusable for the Bureau of Alcohol, Tobacco, Firearms and Explosives to use a controversial tactic known as "gun-walking" in its effort to identify and prosecute major arms trafficking networks along the Southwest border. Justice Department policy has long prohibited the tactic.
The operation's goal was to follow the gun supply chain from small-time gun buyers at a number of Phoenix-area gun shops and make cases against major weapons traffickers. In the process, federal agents lost track of many of the more than 2,000 guns linked to the operation. Two of the guns purchased at a Phoenix gun store were recovered from the scene of a shooting that killed border agent Brian Terry on the U.S. side of the border.
The House Judiciary Committee chairman, Rep. Lamar Smith, R-Texas, said the Justice Department had given inconsistent statements about what Smith called "a reckless and dangerous law enforcement program." Smith said many questions remain about who authorized the operation.
"We do not know who the particular person was" who decided that "this flawed operation should be conducted," Holder said.
Amid probes by Republicans in Congress and the Justice Department's inspector general, the department already has replaced U.S. Attorney Dennis Burke in Phoenix, acting ATF Director Kenneth Melson and the lead prosecutor in Operation Fast and Furious.
Holder said he is prepared to take other steps, with additional personnel changes possible. The inspector general's office at the Justice Department is investigating what went wrong in Operation Fast and Furious, but "that does not lessen the responsibility I have as head manager," he said.
Sensenbrenner told Holder that "I don't want to say you have committed a felony," but pointed to the Justice Department's decision last week withdrawing an inaccurate letter last February to Sen. Chuck Grassley, R-Iowa, the ranking Republican on the Senate Judiciary Committee. The February letter said the ATF makes every effort to intercept weapons that have been purchased illegally -- an assertion that was wrong in the case of Operation Fast and Furious.
No one at the Justice Department was lying, Holder said. He said department officials based their conclusion in the letter on the best information they had at the time from the Phoenix offices of ATF and the U.S. attorney.
Operation Fast and Furious was "a regional operation" and not "top to bottom," said Holder. The tactic at issue was not a decision made in Washington, Holder said.
In explaining why the letter contained inaccuracies, Holder said "we were rushed" in responding to Grassley's inquiries. He said it would have been better to take two weeks to respond rather than the four or five days department lawyers set as their deadline.
Grassley, whose inquiry brought the tactic used in Operation Fast and Furious to light, is calling for Breuer's resignation.
Breuer has said he made a mistake in not telling Holder and the deputy attorney general that the gun-walking tactic had been used in an earlier ATF probe called Operation Wide Receiver, which Breuer had known about since April 2010.
Grassley said that in addition to not informing his superiors, Breuer gave misleading answers when the senator asked whether Breuer had reviewed a draft of the inaccurate Justice Department letter to Congress last February.
Breuer told Congress he cannot say for sure whether he saw a draft of the inaccurate letter and that he has no recollection of having done so. At the time the letter was drafted, Breuer told one of the letter's main drafters in an e-mail, "As usual, great work."
Michael Chertoff, who early in the George W. Bush administration had the job Breuer now holds, spoke out on behalf of Breuer, whom Chertoff has known for over a dozen years.
"He's a very able, dedicated prosecutor," said Chertoff. "He acknowledged he was mistaken in not bringing this issue up to the attorney general at an earlier point in time and that's an admirable thing to do. I understand Sen. Grassley's feelings in this and I respect his feelings, but it would be a loss if Lanny were to leave." In the 1990s, Chertoff was counsel to Republicans on the Senate Whitewater Committee looking into the conduct of then-President Bill Clinton and the first lady during the time Clinton was Arkansas governor.