The hallmark of the Bush administration — its short summary in future history books — is its utter incompetence in all things but one: lying. So it is surprising — and not a little ironic — that a former member of the White House leadership has proved to be a thoroughly incompetent liar.

Worse news for the Bush team: Not only was he caught on tape telling lies badly, he was under oath at the time.

Based on audiotapes of Scooter Libby’s testimony before a Grand Jury that were played this week in his perjury trial in the CIA Leak scandal, we now know that Libby, a former special assistant to Pres. Bush and chief of staff to Vice Pres. Cheney, hadn’t even bothered to work out his false story before he was interrogated.

David Shuster on Countdown Tuesday night described an obvious “tell” in Libby’s lousy performance lying to the Grand Jury:

Scooter Libby, in a very sort of soft and hesitant voice, kept denying that he talked about Valerie Wilson with government officials, and then kept repeating Tim Russert‘s name over and over, as if Russert were Libby‘s holy grail.

Quote, “All I recall that week is that Tim Russert conversation.”

Another quote, “My first recollection is Tim Russert telling me that.” Another quote, “I don‘t recall any other conversations earlier in the week about it.”

Libby’s conversation with Russert, the host of NBC’s Meet the Press, in July 2003, is at the center of the government’s perjury case against him. Libby’s version of events — that Russert was the first to tell him that the wife of an administration critic was a covert CIA agent working in the counterproliferation of terror weapons — had been disputed by six other witnesses in his trial before Russert took the stand yesterday and denied he told Libby the CIA agent’s name.

Here’s Libby’s sworn Grand jury testimony about his converrsation with Tim Russert:

LIBBY: And then he said, you know, did you know that this — excuse me, did you know that Ambassador Wilson’s wife works at the CIA? And I was a little taken aback by that. I remember being taken aback by it. And I said, no, I don’t know that. And I said, no, I don’t know that intentionally because I didn’t want him to take anything I was saying as in any way confirming what he had said, because at that point in time I did not recall that I had ever known this, and I thought this is something that he was telling me that I was first learning. And so I said, no, I don’t know that because I want to be very careful not to confirm it for him, so that he didn’t take my statement as confirmation for him. Now, I had said earlier in the conversation, which I omitted to tell you, that this — you know, as always, Tim, our discussion is off-the-record if that’s okay with you, and he said, that’s fine.

So then he said — I said — he said, sorry — he, Mr. Russert said to me, did you know that Ambassador Wilson’s wife, or his wife, works at the CIA? And I said, no, I don’t know that. And then he said, yeah –yes, all the reporters know it. And I said, again, I don’t know that. I just wanted to be clear that I wasn’t confirming anything for him on this. And you know, I was struck by what he was saying in that he thought it was an important fact, but I didn’t ask him anymore about it, because I didn’t want to be digging in on him.

Your average 15-year-old would have done a better job than wandering around the morass like that. It’s all so implausibly framed that we could almost feel pity for Libby. Didn’t he know he was going to have to lie? A more practiced liar — Pres. Bush, Vice Pres. Cheney or Karl Rove, just to name threee — would have carefully mapped out his fake story before going under oath.

The other interesting question is, why did Libby expect Russert to back him up? If there were any justice, someone would put Russert under oath and ask him why an official in the Office of the Vice President thought Russert willingly risk federal perjury charges for him.