How far will Vice President Cheney go to shield himself and his office from public scrutiny?

Last spring, Cheney asserted that he wasn't subject to executive-branch rules about classified information because he wasn't actually part of the executive branch.

Now his office argues that he and his staff are completely immune from congressional oversight.

That's right: Completely immune.

Cheney's latest claim came in a response to a House Judiciary Committee request for vice presidential chief of staff David S. Addington to testify about his central role in developing the administration's torture policies.

Cheney lawyer Kathryn L. Wheelbarger wrote back:

"Congress lacks the constitutional power to regulate by a law what a Vice President communicates in the performance of the Vice President's official duties, or what a Vice President recommends that a President communicate in the President's performance of official duties, and therefore those matters are not within the Committee's power of inquiry."

As it happens, that was only one of three startling responses in Wheelbarger's letter.

She also wrote:

"The Chief of Staff to the Vice President is an employee of the Vice President, and not the President, and therefore is not in a position to speak on behalf of the President."

Disregard, for a moment, the fact that Addington wasn't actually asked to speak on behalf of the president - but about his "unique information and perspective" Contrary to Wheelbarger's central assertion, Addington actually does work for the president. When he took over the job previously held by Scooter Libby -- who has since been convicted of perjury and obstruction of justice in the Valerie Plame CIA leak case -- Addington also inherited Libby's title as "assistant to the president" See, for instance, his official White House profile.

Cheney's office somehow managed to omit Addington from the White House staff list submitted to Congress. But Addington isn't on Cheney's public Senate payroll either.

Finally, Wheelbarger cites, "separate from any question of immunity from testimony," questions of privilege "protecting state secrets, attorney-client communications, deliberations, and communications among Presidents, Vice Presidents, and their advisers."

In a letter to Addington, Judiciary Committee Chairman John Conyers yesterday lamented Wheelbarger's "legalistic and argumentative response" and warned that if Addington refuses to appear voluntarily, he may be subpoenaed. (Conyers issued the same threat to former Attorney General John Ashcroft and former Justice Department lawyer John Yoo, both of whom also declined to appear voluntarily.)

The Conyers letter cites media reports that describe Addington as the driving force behind the administration's most controversial legal arguments. Among the citations: Jane Mayer in the New Yorker, Phillippe Sands in Vanity Fair, Barton Gellman and Jo Becker in the Washington Post and Chitra Ragavan in U.S. News.

And Conyers notes:

"Vice Presidential staff have previously testified before Congress and I am aware of no authority -- and counsel's letter cites none -- for the proposition that such staff could be immune from testimony before Congress."

He also attempts to turn one of Cheney's arguments against him: "While the issue of the immunity of senior advisors to the President is currently under litigation, there has been no suggestion that such immunity, even if recognized, would reach to the Vice President's office, an entity that, as you well know, is constitutionally quite different from the Office of the President.

"As to privilege, such concerns are traditionally and appropriately raised in response to specific questions and not as a threshold reason to decline a Congressional Committee's invitation to appear."

And Conyers concludes:

"Presumably, you believe that whatever actions you took were necessary and comported with the law; in such circumstances, I cannot imagine why you would decline to appear and set the record straight. The American people deserve no less."

Elana Schor writes for the Guardian:

"The lawyer for US vice-president Dick Cheney claimed today that the Congress lacks any authority to examine his behaviour on the job. . . .

"Ruling out voluntary cooperation by Addington, Cheney lawyer Kathryn Wheelbarger said Cheney's conduct is 'not within the [congressional] committee's power of inquiry' . . . .

"The exception claimed by Cheney's office recalls his attempt last year to evade rules for classified documents by deeming the vice-president's office a hybrid branch of government - both executive and legislative. . . .

"Two witnesses sought by Conyers, former US attorney general John Ashcroft and former US justice department lawyer John Yoo, claimed that their involvement in civil lawsuits related to harsh interrogations allows them to avoid appearing before Congress.

"In letters to attorneys representing Ashcroft and Yoo, Conyers shot down their arguments and indicated he would pursue subpoenas if their clients did not testify at his May 6 hearing.

"'I am aware of no basis for the remarkable claim that pending civil litigation somehow immunises an individual from testifying before Congress,' Conyers wrote."

Carrie Johnson writes in The Washington Post that the resistance to Conyers's requests "marks the latest skirmish in a lengthy battle over the scope of presidential authority and the administration's treatment of detainees. Under Attorney General Michael B. Mukasey and his predecessor, Alberto R. Gonzales, the Justice Department has refused to enforce congressional subpoenas for testimony."

Laurie Kellman writes for the Associated Press: "A previous dispute is being hashed out in federal court, with Conyers' committee suing White House Chief of Staff Josh Bolten and former presidential counsel Harriet Miers for refusing to comply with subpoenas on the firings of federal prosecutors. The White House maintains that their testimony is off-limits from congressional oversight under executive privilege.

"On torture policy, the administration appears no more willing to comply with Conyers' requests for testimony and information."

At one point in the dispute now in federal court, the White House made a similar assertion of complete immunity from oversight -- for former presidential adviser Karl Rove.