Joe Lieberman has spent a lot of time over the past few weeks making a spectacle of his disloyalty to the Democratic Party. He's gone out of his way to announce that he'll filibuster against the public option, preventing the majority that gives him his committee chairmanship from bringing their most important legislation to a vote. Then, as if it weren't already clear, Lieberman wanted make sure everyone knew he'd be stumping for some Republicans in 2010. Just in case, you know, anyone mistakenly thought he was loyal to the caucus that gives him his power in the Senate.

My usual approach is to look for the logic (whether sound or not) behind seemingly irrational or quirky decisions. But plenty of other people have already taken their best shot at finding some clever stratagem buried inside Lieberman's operatic disloyalty, and come up empty. This isn't a smart play at all. Lieberman's constituents are solidly behind the measure he's threatening to torpedo, and behind the President he's defying. He can't get anything close to the deal the Democrats are already giving him from the Republicans, and while the Democratic leadership has been too easy on him there's no percentage in reminding them of that. This isn't business. This is personal.

Lieberman's frustrating and possibly self-destructive behavior is an example of the management riddle I call The Fredo Problem, after the incompetent brother in The Godfather. For those of you who aren't familiar with the movies or the novel, Fredo Corleone is not at all cut out to be a gangster like his father and brothers, but is kept around their organization in progressively-more-marginal roles while his terrifyingly competent little brother runs the business. Predictably, no good comes of this. The Fredo Problem comes from employees who, like Fredo, can't be fired but who also can't advance, because their expectations outstrip their capabilities. Keeping such employees happy is basically impossible. Keeping them loyal to the organization is nearly so.

The Fredo problem isn't simply about incompetence or about ambition, each of which can be managed. It’s about the horrible, unsustainable conjunction of the two. The only thing that a Fredo believes will make him happy is a job that he isn't qualified to get. In fact, Fredos are often mediocre at the jobs they already have, and can't go anywhere else without accepting a big demotion. So they're stuck where they are, and their supervisors and co-workers are stuck with them.

How does this apply to a man who’s a United States Senator, the chairman of the Homeland Security Committee, and seemingly on the Sunday chat shows twice a week? The secret to understanding Lieberman’s behavior is that he expected to be the candidate for President in 2008.

When Lieberman was nominated as Al Gore’s running mate in 2000, he had to indulge himself in some fairly vivid and specific fantasies of running for the big prize, presumably as incumbent Vice-President, in 2008. That dream can be very difficult to let go of. And in each of the national elections since then, Lieberman has made efforts to get on a national ticket. He ran in the Democratic primaries in 2004, losing badly, and clearly negotiated with McCain about joining the Republican ticket in 2008. (Since McCain was considering Lieberman until very late in the process, and only dissuaded from choosing him at the last moment, McCain had to know that his friend from Connecticut would say yes.) That Lieberman would consider defecting to McCain’s losing cause suggests how unrealistically he evaluates his own chances, and how hard it is for him to give up his West Wing dreams. Even Lieberman’s refusal to use his Homeland Security Committee to rein in Bush and Cheney is connected to his own imaginative identification with executive power and his own fantasies of wielding it.

The hard truth is, since Gore made him a national figure, Lieberman hasn’t succeeded much at anything. He was a mediocre running mate in a campaign that did not succeed in gaining the White House. Lieberman certainly isn’t to be blamed for how the Gore campaign went, but neither did he do much good or make any case for himself as a potential nominee. His 2004 campaign quickly became a footnote. (If you don’t remember that he ran: Yes. That’s the problem. And the fact that everyone but Joe himself has forgotten has to rankle.) And then Lieberman had the humiliation of losing his Senate primary and having to run as an independent while begging for campaign help from his Democratic peers (including wunderkind Obama). The last nine years of Lieberman’s political life have been very strange. He’s been brought to the brink of national power, only to have it slip further and further from him with every election cycle. He’s been given the royal treatment by the national press even as his actual political career brings him increasing frustrations and embarrassments. In fact, the more poorly he does, the more the TV pundits revere him. The cognitive dissonance must be dizzying, and the cycle of flattery and rejection in ever-increasing doses would be enough to erode most people’s judgment.

Worst of all, from Lieberman’s perspective, is that he’s been leapfrogged by an upstart, Barack Obama, who was entirely unknown when Lieberman got his first addictive taste of national glory. (As Fredo Corleone puts it, “You’re my kid brother! I was passed over!”) To Lieberman, who on some level believes he should have become president, the ascent of a youngster who in Lieberman’s mind wasn’t even supposed to be running is a particular affront. And being defeated by a politician from a younger generation makes it painfully apparent that Lieberman’s presidential hopes will never, ever bear fruit. If it seems to you unrealistic that Lieberman could ever imagine himself beating Obama, or think of himself as the rightful heir apparent, well, yes. Unrealistic ambition is the heart of Fredo-hood. Honest self-evaluation, which is the only path out of the Fredo Syndrome, is simply too painful, and the Fredo fights harder and harder to protect his fragile ego.

(Interestingly, defeated Vice-Presidential nominees have seemed more likely to turn into Fredos recently than defeated Presidential nominees have. John Kerry has become a good soldier for Obama, and seems to find chairing the Foreign Relations Committee honorable and engrossing, even if he had hoped for more. Al Gore has turned aside from presidential ambition and found enormous rewards along his new path. Meanwhile, the never-ready-for-prime time John Edwards has devolved into a petty schemer who can’t even count the cards in his own hand, making Barack Obama and Hillary Clinton offers they can refuse with laughable ease. Sarah Palin, a running mate so bad that her damage to the ticket can be measured by polls, has become the most spectacular Fredo of our time: Il Fredo di tutti Fredi, or if one prefers La Freda del Freddo. Maybe it’s that vice-presidential candidates can blame their principals and fantasize about another chance, while defeated presidential nominees know they’ve had their last shot, and that they’ve made their own decisions.)

Obama’s challenge in wrangling Lieberman is comparable to taking a job managing an employee who’s applied unsuccessfully for your job twice, and then barely held onto his own job after your predecessor tried to fire him. Harry Reid’s job is even less palatable, like trying to manage someone who’s applied for your boss’s job twice, survived one attempt to fire him for insubordination, and believes in his heart that you should be reporting to him and not the other way around. If it sounds insoluble, it is. The Godfather films offer no solution to this problem. (The end of The Godfather, Part II does not actually represent a plan. The Fredo problem is simply allowed to fester until it become completely insupportable and ends with the worst possible result for everyone.)

Fredos are almost inevitably disloyal, even when the people they betray their organization to offer them much less than the organization itself does. The Fredo can be bought with attention and flattery, by making him feel important. The home team, no matter how generously they treat the Fredo, will always be a source of wounded pride. That Barack Obama helped Lieberman when he was down in Connecticut gets him less than nothing; reminding Lieberman of that only reminds Lieberman of being down. John McCain’s expressed desire to put Lieberman on a doomed ticket earned McCain attack-dog loyalty even though McCain didn’t follow through. Lieberman was willing to do the surrogate dirty work for McCain, who had given him nothing, that Lieberman had been unwilling to do for Al Gore when it counted. The key is that McCain treated Lieberman as a serious contender, White House material, while the Democrats had long since stopped thinking of Lieberman that way.

There is no way to fix this as long as Lieberman remains in both denial and the Senate. And, as Puzo’s Godfather suggests, disloyalty can become an identity that is nearly impossible to abandon. Disloyalty only makes the Fredo more unhappy with himself, and more resentful, because it makes it even harder for the Fredo to examine himself honestly. You might forgive a traitor, as Tom Hagen puts it near the end of Puzo’s novel, “but people never forgive themselves, and so they [will] always be dangerous.”