Former White House spokesman Scott McClellan told Congress Friday that the Bush-Cheney Administration continues to conceal information about abuses of power committed to punish former Ambassador Joe Wilson for challenging the President’s storyline with regard to the “need” to invade and occupy Iraq.

“This matter continues to be investigated by Congress because of what the White House has chosen to conceal from the public,” McClellan told the House Judiciary Committee. “Despite assurances that the administration would discuss the matter once the special counsel had completed his work, the White House has sought to avoid public scrutiny and accountability.”

Speaking under oath, the longtime aide to President Bush seemed at times to dumb down his testimony, softening points made in his explosive book, What Happened: Inside the Bush White House and Washington’s Culture of Deception.

In the book and in interviews promoting it, McClellan suggested that key players in the White House — including political czar Karl Rove, vice presidential chief of staff Lewis “Scooter” Libby and Vice President Dick Cheney — had at critical points in 2003 lied to him (or, at the least, conspired to keep him in the dark) about their involvement in the leaking information about the fact that Wilson’s wife, Valerie Plame Wilson, was a CIA covert operative.

Before the committee, the former spokesman was more cautious.

“I do not know whether a crime was committed by any of the administration officials who revealed (Wilson’s wife) Valerie Plame’s identity to reporters. Nor do I know if there was an attempt by any person or persons to engage in a cover-up during the investigation. I do know that it was wrong to reveal her identity, because it compromised the effectiveness of a covert official for political reasons.”

McClellan specifically attempted to absolve President Bush, while keeping open the prospect that Cheney was an active conspirator. “I do not think the president had any knowledge (of the efforts to harm Wilson by leaking his wife’s identity),” the former spokesman said. “In terms of the vice president, I do not know.”

McClellan’s testimony confirmed Libby’s role in the campaign to discredit Wilson. And he raised new questions about former White House Chief of Staff Andy Card’s involvement in the wrongdoing.

Speaking of Libby, who in 2007 was convicted of perjury, lying to federal investigators and obstruction of justice with regard to his involvement with the plot to out Plame Wilson, McClellan said: “He assured me in unequivocal terms that he was not (involved), meaning the leaking of Valerie Plame’s identity to any reporters, and then I contacted reporters to let them know about that information.”

“But,” the former spokesman continued, “it was Andy Card that had directed me to do that, at the request of the president and vice president.”

If that sounds like a contradiction — McClellan first suggests Bush had no knowledge of the initiative and then says that he peddled false information at the behest of the President — it may be. Then again, it is possible that Bush was lied to, as well.

What is clear, however, is that McClellan has provided a baseline of information upon which the Judiciary Committee can and should build a more serious investigation into White House wrongdoing.

Andy Card should be called to testify.

The White House did not invoke a dubious claim to executive privilege to block McClellan’s testimony because, Administration aides told CNN, the president and his team determined that “there’s nothing new” in their former colleague’s testimony.

Fair enough.

Then Card should testify, under oath, about the same matters that McClellan discussed. And if clarity is not achieved, then more members of the Administration should be called.

The committee should get clear about the fact that the founders intended Congress to have the authority to compel testimony by all members of the executive branch, including presidents and vice presidents, when Constitutional questions are in play.

The committee should, as well, get clear on its focus and responsibility.

The job of the House Judiciary Committee when conducting an inquiry of this sort is not to look for specific violations of statutes or the Common Law. The committee is not a congressional version of a criminal investigator.

The job of the committee is to examine whether high crimes and misdemeanors — the term of art for assaults on the Constitution and the rule of law — have been committed. The use of an executive position to punish a critic of a monarch or a president is a classic example of a high crime in the traditional sense. And that reading of the language of the Constitution was reaffirmed by the bipartisan House Judiciary Committee votes of 1974 to impeach Richard Nixon for using his office to achieve similar political ends.

The Constitutionally-dictated system of checks and balances requires that Congress hold the executive branch to a higher standard than merely not getting caught committing petty or even serious crimes. The job of the Judiciary Committee is to determine whether the president, the vice president and their aides are operating in a manner that upsets the separation of powers and undermines the functioning of the federal government according to the plan established by the founders in the Constitution and its supporting documents.

McClellan tells Congress that the Bush-Cheney White House “has chosen to conceal (information about abuses of power) from the public.”

McClellan tells Congress that “the White House has sought to avoid public scrutiny and accountability.”

It is the responsibility of the Judiciary Committee to apply scrutiny and to demand accountability — and to recognize that, if the current president and vice president continue to stonewall Congress, then they should face the same sanctions as were applied to Nixon.

Step one is to call Andy Card to testify. That’s a natural progression from today’s session, and the only way to answer compelling questions raised by McClellan’s testimony.

From there, the committee should follow the trail, without apology or compromise, wherever it leads.

While they are at it, Judiciary Committee members ought to acknowledge the obvious: When the former spokesman for the president and the vice president says “the White House has chosen to conceal (information about abuses of power) from the public,” this is no longer an inquiry into leaks about the identity of a CIA operative.

This is an investigation of abuses of power at the highest levels of the executive branch. It is, as such, an examination of the sort of high crimes and misdemeanors for which previous presidents have faced the live threat of impeachment.

To sugarcoat that fact is to insult not just the intents of the founders but the American people, who still believe that an oath to defend and uphold the Constitution should amount to more than just a mumbled phrase on inauguration day.