It's all about Joe

That's not exactly true, it's all about the corporatist soft neocons of the Democratic Party establishment in DC.
Lieberman says he'll collect signatures for independent campaign

Facing a stronger-than-expected Democratic primary challenge and sagging poll numbers because of his support of the Iraq war, U.S. Sen. Joe Lieberman said Monday he'll collect signatures for an independent campaign if he loses next month's primary.

Of course this is no real surprise nor is it a surprise that Check Schumer and Harry Reid and the rest of the DSCC are supporting Lieberman and will support him even if he loses the primary and runs as an independent. This is not about the will of the people, the will of the Democratic Party rank and file, this is all about power. Those who have it don't want to give it up, Republican or Democrat. The establishment's support of Lieberman will insure that the Democratic Party will remain a minority party. If people want a Republican they will vote for a Republican. With the DLC crowd lead by Marshall Wittmann, Joe Lieberman and Hillary Clinton remain in charge Ralph Nader will have been proven right, there is no difference between the two parties.