(updated below)

There are few things more boring than following the twists and turns of the Campaign Scandal du jour, but this is pretty unstable behavior:

Fox News on Wednesday:

John McCain will suspend his presidential campaign Thursday and has asked to postpone his debate Friday with Barack Obama so the two senators can return to Washington to help negotiate a Wall Street bailout, an approach that Obama promptly rejected.

McCain will participate in Friday night's debate if a bill is passed by Friday morning, his adviser Mark Salter said.

Associated Press yesterday:

His campaign has said he wouldn't participate unless there was consensus between Congress and the administration, and a spokesman said the afternoon developments had not changed his plans. . . .

"There's no deal until there's a deal. We're optimistic but we want to get this thing done," McCain spokesman Brian Rogers said.

The New York Times today:

Talks Implode During a Day of Chaos; Fate of Bailout Plan Remains Unresolved

Separately, Representative Barney Frank, Democrat of Massachusetts, and the chairman of the House Financial Services Committee, said on Friday that an agreement depended on House Republicans’ ending their opposition and “dropping this revolt” against the plan proposed by the Bush administration, The Associated Press reported. He described the rival plan being proposed by Republicans as “an ambush.”

Meanwhile, Senator Richard C. Shelby of Alabama, the senior Republican on the banking committee and a critic of the current plan, said the plan had to change before it would win support of Republicans.

In an interview on CNBC, quoted by Reuters, Mr. Shelby said, “This is not going to work.”

The Politico, an hour ago:

McCain will go to debate

Sen. John McCain (R-Ariz.) ended three days of suspense on Friday morning and announced that he will leave bailout negotiations in Washington and fly to Oxford, Miss., for tonight's opening presidential debate.

McCain had previously said that he would suspend his campaign -- and so would not attend the debate -- until an agreement was reached on the administration's $700 billion mortgage proposal. No such agreement has been reached, but Republicans said the standoff was hurting McCain's campaign and that he would look terrible if he didn't attend the nationally televised, eagerly anticipated debate, while Sen. Barack Obama (D-Ill.) was ready to go on stage.

In less than 48 hours, McCain went from "I'm far too patriotic to debate unless there is a deal that is done -- there's no deal until there's a deal" to "I'm going to debate even though there's no deal." Is there any way to describe that other than, as Spencer Ackerman put it, a "humiliating failure"? The New York Times's Patrick Healy today inanely ponders whether "In a Time of Crisis, Is Obama Too Cool?" (Didn't Rudy Giuliani become the Greatest Man Ever in History because of his post-9/11 coolness?) But surely excessive stoicism is vastly preferable to the sort of unstable, flailing panic that McCain has exhibited this week, where he issues a definitive, emphatic pledge which, less than 2 days later, is completely abandoned with little real explanation.

UPDATE: On Wednesday, Joan Walsh said McCain's debate announcement was a "crazy stunt" and "he will regret it." I doubt she knew how right she was. In addition to the above, National Review's Rich Lowry adds yet another reason why this is so:

A Hostile Audience

One side effect of McCain's debate gambit is, I'm told, that everyone at Ole Miss now hates him. It will make for a very hostile audience tonight among those students and faculty attending. He might have to apologize for creating the uncertainty or make some explanation up front, which is never ideal.

It's understandable that McCain is trying to run an unconventional campaign -- it's the only way he has any chance to win, and it's why I thought and still think his Palin choice was shrewd, even if it ultimately doesn't work out -- but this "I'm-not-debating-yes-I-am" maneuver was just a total debacle on every level, and -- like Palin -- McCain is becoming an almost pitiable figure.