Four hours after the news broke that he’s quitting, I’m still in shock. Help me figure this out. Three possible reasons why he’d retire now:

1. He was destined to lose in November. Nonsense. He has a huge war chest, a respected family brand, a reputation for centrism to give him some distance from Obama, and an opponent in Dan Coats whose name recognition is much lower than his own. He would have had to explain his vote on ObamaCare but siding with the GOP on a bunch of issues this year would have eased the blow of that. Plus, he’s never lost an election. If Pence had jumped in, I might have bought this as an explanation. As it is, nuh uh.

2. He wants to be president. Undoubtedly true — the money line from the clip is “I am an executive at heart” — but how does quitting get him closer to his goal? Could be that he thought that losing to Coats would taint him as a loser ahead of 2016, but Nixon did okay after losing in 1960 and 1962. Besides, given liberals’ contempt for him, losing to a Republican would have a small silver lining of reminding progressives that he is, in fact, sufficiently to the left of the GOP to make him vulnerable in a Republican wave.

As for a primary challenge to Obama in 2012, please. Obama’s problem among Democrats isn’t with the center, it’s with the left; a challenge from Bayh would force liberals to grudgingly unite behind The One, which, combined with support from young voters and minority voters, would carry him through. (Don’t forget that O will be forced to tack right next year after the GOP picks up seats in Congress, so Bayh’s appeal as a centrist alternative come 2012 will be blunted.) Meanwhile, the Dem establishment would be royally pissed that anyone would try to weaken Obama ahead of a tough general election campaign. In which case, why would Bayh risk his chances in 2016 at a quixotic 2012 bid? And why, if he needs to build bridges inside the party for a future run, would he reportedly sandbag the Dems by not telling them of his decision until three days after he made it? He’s put them in a horrible position here, not only by making them scramble to recruit a candidate but by boosting the GOP’s chances to retake the Senate considerably. Not a smart move for a guy thinking about a nomination down the line.

3. Congress really is a total drag. I’m inclined to think he’s telling the truth and that he really is sick and tired of gridlock. But if he wants to be president, why not suck it up for another six years? He’s already been governor so there’s nothing left for him to run for; it’s possible that he thinks quitting now will set him up as a Beltway “outsider” for 2016, but it’s going to so lower his profile that people may not remember who he is by then. I wonder if the prospect of Republican gains next year forced his hand: In a closely divided Senate, he’ll wield considerable power but also be forced to cast votes that will further alienate the left, something he can’t afford to do if he’s thinking about a presidential run down the line. One intriguing footnote via a Dem operative who spoke to Politico: Supposedly, Bayh was scheduled to start shooting ads for his reelection campaign on Wednesday. If disgust with Congress is really the reason he’s retiring, why did it take until the eleventh hour for him to realize it?

The only thing more mystifying to me than Bayh’s retirement is Mike Pence’s decision to stay out of the race. He’s a tea-party darling and he’ll never have a more favorable political climate to run than in November. If not now, when?

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