Holder and Rep. Issa Clash Again Over Fast and Furious Photographs by Stephen Crowley/The New York Times During a hearing on Operation Fast and Furious, Representative Darrell Issa, left, chastised Attorney General Eric H. Holder Jr., referencing "whistle-blowers that are tired of your stonewalling." WASHINGTON - Representative Darrell Issa told Attorney General Eric H. Holder Jr. on Thursday that he was "not a good witness" as the two clashed once again over the botched gun trafficking case known as Operation Fast and Furious. In a hearing before the House Judiciary Committee, Mr. Issa, a California Republican, chastised Mr. Holder as having failed to directly answer a question about whether the department had gathered and indexed all the materials asked for in a subpoena he issued last fall. Mr. Issa has threatened to cite Mr. Holder with contempt. When Mr. Holder stressed that he had already testified eight times about Fast and Furious and that the department had produced more than 7,600 pages of documents, Mr. Issa cut him off, "Look, I don't want to hear about the 7,600." Republicans pressed Mr. Holder about when senior officials learned that agents of the Bureau of Alcohol, Tobacco, Firearms and Explosives in Arizona who were working on the case were using the tactic of "gun walking" - allowing guns to remain on the street, rather than swiftly interdicting them, in order to build a bigger case. Mr. Holder said officials learned about the tactics in early 2011, after two Fast and Furious-linked guns were found near a shootout in which a Border Patrol agent, Brian Terry, was killed in December 2010. Last year, Mr. Holder replaced the leadership at the firearms bureau and ordered an inspector general investigation. He said that report might clear up who authorized the tactics and that it should be out "relatively soon." Republicans, however, expressed skepticism that senior Obama administration officials had not authorized - or at least known about - the tactics. Democrats pushed back, pointing out that A.T.F. agents used similar tactics in other Arizona cases during the Bush administration. "I believe that the effort here has become politically motivated in an attempt to embarrass the administration," said Representative Mike Quigley, Democrat of Illinois. Mr. Issa focused on court-sealed wiretap applications for Fast and Furious, telling Mr. Holder he had obtained them from "whistle-blowers that are tired of your stonewalling." He said the documents - reviewed by senior department officials in 2010 - made clear that guns were being walked. But Mr. Holder said that senior officials reviewed only summaries of the applications. And, he said, even the underlying materials did not show that "these inappropriate tactics were being used." Mr. Holder is associated with some of the administration's most liberal policies, from blocking voter identification laws to refusing to defend a statute barring federal recognition of same-sex marriages. Some conservatives are eager for the Republican House to cite him with contempt, a step that could have unpredictable consequences amid the run-up to the election. Last month, House Republican leaders - including Speaker John A. Boehner - sent Mr. Holder a letter about the subpoena, prompting staff-level talks between Mr. Holder's office and House Republican leaders. A reply by Mr. Holder's deputy praised the talks as constructive, and Mr. Holder expressed confidence on Thursday that they could "result in a mutually acceptable resolution." But Michael Steel, a spokesman for Mr. Boehner, said: "There have not been any substantive talks at all, or any response from the attorney general to the speaker. We are still waiting for accountability.