The House of Representatives prepared to cite Attorney General Eric H. Holder Jr. for contempt of Congress on Thursday afternoon, opening an acrimonious debate on the chamber floor over a Republican push to impose that sanction for the first time on a sitting member of a president’s cabinet.

The politically and constitutionally charged dispute centers on whether the Justice Department must turn over e-mails and memorandums showing its internal deliberations last year as officials grappled with a Congressional investigation about the botched Arizona-based gunrunning investigation known as Operation Fast and Furious. President Obama has invoked executive privilege to block the subpoena.
In early jostling – a debate over the rule governing the final debate later in the day – Republicans repeatedly invoked the death of Brian Terry, a border patrol agent killed in a shootout in December 2010. Two guns that had been purchased by a suspect in the gunrunning case the previous January were found the near the scene.
“These contempt charges aren’t about politics,” said Representative Rich Nugent, Republican of Florida. “They aren’t about Attorney General Holder or President Obama or anything else but this: A man died serving his country and we have a right to know what the federal government’s hand was in that. It’s clear this country somehow played a role in his death. We need to root it out, find the cause, and make sure this never, ever happens again.”
Democrats dismissed the effort as an election-year witch hunt. They said previously disclosed documents and testimony had established that Operation Fast and Furious was the work of Arizona-based law enforcement officials who were frustrated by the difficulty of bringing low-level gun cases, and they contended that Republicans were seeking to embarrass Mr. Holder for political reasons.
With Republicans in the majority in the House, there was little doubt that the final vote, expected late on Thursday afternoon, would be to cite Mr. Holder for contempt, as well as to authorize a lawsuit asking a judge to order the Justice Department to turn over the documents.
The only question was how many Democrats representing conservative-leaning districts would cross party lines to join in citing Mr. Holder. The National Rifle Association was pressuring them to do so, announcing that it would score the vote in its report card on how lawmakers approached Second Amendment gun rights.
The Congressional Black Caucus was planning to stage a walkout during the vote, and it appeared that other Democrats might join them. In 2008, when the Democratic-led House cited two Bush administration officials for contempt in a dispute over information related to a mass firing of United States attorneys, many Republicans did likewise. "We’re going to make it clear we’re disappointed with the process and the superficiality with which this matter has been dealt with,” Steny H. Hoyer, Democrat of Maryland, the House minority whip, said Thursday.
A citation for contempt of Congress carries symbolic weight, but its practical impact is limited because the executive branch controls prosecution decisions.
In the 2008 case, when the parties’ positions were reversed, Attorney General Michael B. Mukasey wrote a letter to Nancy Pelosi, then the House speaker, saying that prosecutors would not convene a grand jury or charge the two officials who were cited, because Mr. Bush had invoked executive privilege over the information Congress had subpoenaed so the Justice Department did not consider their failure to provide the information a crime.
The Obama Justice Department has been preparing a similarly worded letter to the current House speaker, John A. Boehner, according to officials familiar with the internal discussions. Because the contempt citation was leveled against Mr. Holder, it appeared that the letter would be signed by the deputy attorney general, James Cole, and would be sent either late Thursday or on Friday, the officials said.
“What Republicans are doing with this motion today is contemptible," Ms. Pelosi said. "Even for them, it’s contemptible.” She made clear she would be staying long enough to cast her vote against the resolution before joining other Democrats in a walkout.
Operation Fast and Furious was an investigation by Phoenix-based agents of the Bureau of Alcohol Tobacco, Firearms and Explosives into a gun-smuggling network that recruited low-level “straw buyers” – people without criminal records who could lawfully purchase weapons – to buy guns, which it then funneled to a Mexican drug cartel.
The investigation, which ran from late 2009 to early 2011, is controversial because investigators – frustrated at the difficulty of bringing cases against suspected straw buyers – are said to have used the risky tactic of “gunwalking,” meaning they sometimes failed to swiftly interdict weapons and arrest low-level suspects because they were trying to build a bigger case.
The suspects under scrutiny ended up purchasing about 2,000 guns, most of which are presumed to have reached drug gangs. In December 2010, two weapons that had been purchased by one of the suspected straw buyers for the network was found at the site of a shootout in which Mr. Terry was killed.
Information has since emerged that the Phoenix division of the A.T.F. had a dispute with Arizona-based federal prosecutors over how much evidence was necessary to bring charges in straw-purchasing cases, and that the division had used similar tactics in at least three other investigations late in the Bush administration – though none of those lost track of as many weapons as Fast and Furious.
Mr. Holder, a recurring target for Republicans, is associated with some of the administration’s most liberal policies on matters like gay rights, civilian trials in terrorism cases and the enforcement of civil rights laws. He has also opposed state voter photo identification requirements.
At a raucous rules committee meeting on Wednesday, Representative Darrell Issa, the California Republican who is leading the investigation as chairman of the House Oversight Committee, said that “during the inception and the participation through the death of Brian Terry, we have no evidence nor do we currently have strong suspicions” that Mr. Holder knew of or authorized the tactics used in the investigation.
Still, Mr. Issa said, he wanted to know more about whether other Justice Department officials knew or should have known about them. The contempt citation focuses on internal e-mails and memos from February to December 2011, after the operation in Arizona ended and as department officials in Washington were struggling with the Congressional investigation into it.
The Obama administration has declined to release the documents, invoking a form of executive privilege that protects agency deliberations from disclosure in order to preserve the candor of internal executive branch discussions.
There is little Supreme Court precedent to guide how far that form of the privilege – which is considered to be weaker than a form that protects communications involving the president and the White House – extends in response to a Congressional subpoena.
Despite Mr. Obama’s assertion of executive privilege, the Justice Department has offered to give Congress several hundred of the disputed documents if Republicans scrap the contempt recommendation. The White House on Tuesday allowed Republican staffers to scan about a dozen of them, which it portrayed as a representative sample. But the two sides failed to reach a deal.