Behind the legal argument is a political dispute. House GOP leaders are pressing for a contempt vote against Holder that is tentatively scheduled for Thursday, the same day the Supreme Court will rule on the legality of the nation's health-care law.
Rep. Steny Hoyer of Maryland, the House Democrats' chief head counter, said he expected some Democrats to follow the National Rifle Association's call for a "yes" vote on contempt. The NRA has written to all members of Congress, saying the White House wanted to use the Operation Fast and Furious gun-tracking operation to advance a gun-control agenda.
Hoyer would not give a number of potential defectors.
At a news conference, civil rights leaders said Holder is being targeted by Republicans because he has aggressively enforced laws guaranteeing the right to vote.
Holder's opponents want to "put a cloud over his head" and they want to see "if they can slow him down," said the Rev. Al Sharpton. Among the other participants were the heads of the Leadership Conference on Civil and Human Rights, the Urban League, the NAACP, and the National Council of La Raza.
In a letter to the president dated Monday and made public Tuesday, Issa cited an appellate court decision to back his claim and questioned whether Obama was asserting a presidential power "solely for the purpose of further obstructing a congressional investigation."
White House spokesman Eric Schultz said Tuesday that Issa's analysis "has as much merit as his absurd contention that Operation Fast and Furious was created in order to promote gun control. Our position is consistent with executive branch legal precedent for the past three decades spanning administrations of both parties."
Courts have routinely "affirmed the right of the executive branch to invoke the privilege even when White House documents are not involved," Schultz said.
Some experts agree with the president's view that all executive branch documents are protected from disclosure. Ohio State University law professor Peter Shane, a specialist in presidential power, says executive privilege historically covers documents generated anywhere in the executive branch.
Holder's offer last week to turn over some documents - the Justice Department has provided 7,600 records so far - was rejected by Issa because he contended the attorney general was demanding an end to the panel's probe.
The documents at the heart of the current argument are not directly related to the workings of Operation Fast and Furious, which allowed guns to "walk" from Arizona to Mexico in hopes they could be tracked.
Rather, Issa wants internal communications from February 2011, when the administration denied knowledge of gun-walking, to the end of the year, when officials acknowledged the denial was in error. Those documents covered a period after Fast and Furious was shut down.
In Fast and Furious, agents of the federal Bureau of Alcohol, Tobacco, Firearms and Explosives in Arizona abandoned the agency's usual practice of intercepting all weapons they believed to be illicitly purchased.