Rahm said he wanted the job months ago and now suddenly Daley doesn’t want the job anymore, and, oh, everything’s working out perfectly!

“The truth is I have been thinking about this for the past several months,” Daley said at a City Hall news conference. “In the end this is a personal decision, no more, no less.”

His wife Maggie stood by his side with the help of a crutch, smiling broadly as the mayor continued: “I have always known that people want you to work hard for them. Clearly, they won’t always agree with you. Obviously, they don’t like it when you make a mistake. But at all times, they expect you to lead, to make difficult decisions, rooted in what’s right for them…

“Simply put, it’s time,” said Daley, 68. “Time for me, it’s time for Chicago to move on.”…

Daley’s public approval rating had dipped recently, with a Tribune poll earlier this summer showing that more than half of Chicago voters said they don’t want to see him re-elected.

Three possibilities. One: He was tired of the job and wants to move on. I don’t buy it, partly because it’s antithetical to how machine politicians think and partly because Daley’s a relatively spry 68 years old. (His old man, who naturally died in office, was 74.) Two: He’s afraid that his declining poll numbers plus the big red tsunami that’s on its way could lead to an ignominious defeat when the mayoral election is held in February. I don’t buy that either, as Chicago hasn’t voted Republican in more than 80 years. Three: Emanuel knows that Obama’s going to shake up the White House after November’s bloodbath and, fairly or not, as chief of staff he’ll take plenty of blame. Dumping Rahm will help soothe the left, which hates him almost as much as he hates them. So, anticipating all that, maybe he and Daley made some sort of deal to clear the way for him? I don’t buy that theory either, actually, because if Daley was angling to make Rahm his successor, he would have held off on announcing this until later this year. The filing deadline for the election isn’t until November 22; by dropping this now, Daley gives other Democratic contenders time to weigh bids of their own and kicks off endless distracting speculation about whose heads are on the chopping block in the White House. To be sure, that speculation has already started — last week Chris Matthews goofily suggested Mike Bloomberg as Rahm’s replacement due to his “communications pizazz” — but now it’s going to rev up fast. Very, very strange. Maybe my first theory is the correct one after all?

The good news for Chicagoans: Whoever comes next probably can’t do any worse than Daley. For your viewing pleasure, below you’ll find a bit more speculation on the, ahem, “soul-searching” to come inside the White House after they get hammered on election day. Note that Podesta said it this morning, before the Daley announcement and subsequent Rahm frenzy kicked off. Exit question: Who’s going to replace Rahm as COS? Tom Daschle’s name was kicked around in 2008 but he’s a health-care guy and they’ve already checked that box, and besides, they don’t want to have to deal with his tax baggage. If The One’s planning on tacking right to deal with the new Republican Congress, presumably he’ll want someone as centrist as Rahm, no?

Update: Here we go. Bye, Rahm.

Meanwhile, a senior Obama Administration official said Emanuel is likely to run for the post.

“I’d be shocked if he doesn’t run,” the official said…

Conversations with plugged-in Chicago Democrats — and boy are there lots of them! — make clear that if Emanuel ran, he would be the clear frontrunner although almost certainly wouldn’t have the field entirely to himself.

Emanuel’s just 50 years old, so assuming he wins, pencil in him as mayor until, oh, 2045 or so.

Update: Let the distracting speculation begin!

Emanuel has told Chicago associates, a source tells me, who he believes will likely succeed him: Senior Obama adviser Valerie Jarrett.

Other internal names have risen and fallen: Peter Orszag was viewed, for an early moment, as a likely successor; Jim Messina is also a candidate, though bad midterms would do him damage as well; Tom Daschle has the requisite stature and connections on the Hill; John Podesta, who has said he doesn’t want the job, would represent a change of course.