Watching Republican Senator Arlen Specter challenge Bush administration wrong-doing is like witnessing a failed rocket launch. After the initial furious explosion of hot air, Specter almost immediately loses momentum and never breaks the dark gravitational pull of planet Bush.

Specter's performance Thursday during the Senate Judiciary Committee's debate over issuing White House subpoenas in the firing of U.S. attorneys was certainly no exception.

After the testimony two weeks ago of six of the fired prosecutors, Specter joined the bipartisan chorus of frustration with Attorney General Alberto Gonzales, "One day there will be a new attorney general, maybe sooner rather than later." But by this week, he changed his tune, furiously backpedaling as Judiciary Committee Chairman Pat Leahy (D-VT) pressed for issuing subpoenas to Karl Rove, Harriet Miers and other Bush White House officials.

During the heated session, Specter argued for avoiding confrontation with the White House at all costs. While Leahy angrily described the President's offer of closed-door interviews conducted without oaths or transcripts as "nothing, nothing, nothing," Specter suggested the committee go along to get along. "If we have the confrontation," he said, "we are not going to get this information for a long time." The conflicted Pennsylvania Republican then proposed total concession to President Bush framed as a compromise, suggesting that the committee insist only on transcripts.

In the end, the Democrats on the Judiciary Committee along with Iowa Republican Chuck Grassley voted to authorize the subpoenas. But as Paul Kane describes in the Washington Post, a chastened and frozen Arlen Specter abstained from the vote. Afterwards, Specter initially refused to disclose his position to reporters. Ultimately, though, Specter owned up to his staggering act of political cowardice:

But Specter had a change of heart and decided to clear the air, tracking down a few reporters. He did not deny that his mouth might have opened during the call for "ayes", but Specter denied saying anything, uttering any sound.

"The fact of the matter is that I did not say anything. I did not vote and say either 'aye' or 'nay'. I just sat there hoping that it would all go away through negotiations," he said. "Factually, I did not say a thing."

Arlen Specter's tortured cognitive dissonance over the politically motivated firings of U.S. attorneys may be the by-product of his own essential role in making the scandal possible in the first place. As Dahlia Lithwick detailed in Slate ("Specter Detector"), it was Specter's own chief-of-staff and former Clarence Thomas clerk Michael O'Neill who at the urging of the DOJ surreptitiously inserted the codicil into the revised Patriot Act enabling the Attorney General to name interim U.S. prosecutors without Senate confirmation. Specter deflected charges of his own culpability by claiming cluelessness; the Patriot Act proviso significantly augmenting executive power appeared without his knowledge:

"I then contacted my very able chief counsel, Michael O'Neill, to find out exactly what had happened. And Mr. O'Neill advised me that the requested change had come from the Department of Justice, that it had been handled by Brett Tolman, who is now the U.S. attorney for Utah, and that the change had been requested by the Department of Justice because there had been difficulty with the replacement of a U.S. attorney in South Dakota...I did not slip it in and I do not slip things in. That is not my practice. If there is some item which I have any idea is controversial I tell everybody about it."

The change to the Patriot Act was controversial to be sure, the necessary and sufficient condition enabling Alberto Gonzales to undertake his purge of Bush non-loyalists from the ranks of the U.S. attorneys. Mercifully, Specter took the first baby step towards redressing his wrong by joining 93 of his colleagues in stripping the AG's new powers from the Act.

Specter's history of crumbling in the face of withering pressure from the Bush White House is a long and sad one. His reaction to President Bush's illegal program o NSA domestic surveillance is typical. In December 2005, Specter concluded, "There is no doubt that this is inappropriate." But by July 2006, Specter was advocating a "compromise" codifying and forgiving President Bush's violation of FISA laws regarding warrants for domestic eavesdropping. Last April, Specter decried the selective leaking of portions of the 2002 Iraq National Intelligence Estimate by the White House to attack Joe Wilson for his debunking of the bogus uranium in Niger claim. Urging the White House to "come clean," Specter grandstanded, "I think that it is necessary for the president and the vice president to tell the American people exactly what happened." Just one month later, Specter howled about Bush's unprecedented use of presidential signing statements, declaring "'What's the point of having a statute if...the president can cherry-pick what he likes and what he doesn't like?" In both cases, Specter's early outcry was followed by prolonged silence.

Specter's pattern of outrage-turned-to-acquiescence is by now a familiar one. His short-lived anger at Bush administration crimes never reaches exit velocity, leaving him firmly within the orbit of the Republican Party. The scandal surrounding the U.S. attorney firings, as in so many previous instances of GOP malfeasance, is just another case of Arlen Specter's failure to launch.

UPDATE: WIth the revelation that Alberto Gonzales lied about playing no role in discussions surrounding the U.S. attorney firings, Arlen Specter has commenced another cycle on short-lived outrage. "If we find out he's not been candid and truthful," Specter said on March 25, "that's a very compelling reason for him not to stay on." Spencer went on to say that Gonzales' April 17 testimony would be a "make or break" moment for his continued support of the Attorney General. Stay tuned.