Steve Benen suggests that Joe Lieberman's motive for begging to keep his chairmanship could be somewhat sinister:

[T]ake a moment to consider what the Senate Committee on Homeland Security and Governmental Affairs actually does: it's the committee principally responsible for oversight of the executive branch. It's an accountability committee, charged with investigating the conduct of the White House and the president's administration.

As chairman of this committee for the last two years, Lieberman decided not to pursue any accusations of wrongdoing against the Bush administration. Lieberman's House counterpart -- Rep. Henry Waxman's Oversight Committee -- was a vigilant watchdog, holding hearings, issuing subpoenas, and launching multiple investigations. Lieberman preferred to let his committee do no real work at all. It was arguably the most pathetic display of this Congress.

And yet, now Lieberman acts as if keeping this chairmanship is the single most important part of his public life. Why would he be so desperate to keep the gavel of a committee he hasn't used? I'll let you in on a secret: he wants to start using the power of this committee against Obama.

But Ezra Klein takes a slightly different view in response:

I don't think that's quite right. Rather, Lieberman wants to keep his committee as a hedge against retribution. So long as he controls Governmental Affairs, he's not the sort of guy Democrats want on a warpath against them. Elsewhere, they can take him seriously, or screw him over, largely as they please, which most would probably find a preferable alternative.

(via Sullivan)