Senator Lieberman, you are no Zell Miller.
Quoth Dick Durbin in The Hill:
“We have one difference of opinion, maybe two with Sen. Lieberman,” said Senate Majority Whip Dick Durbin (D-Ill.), a prominent supporter of Sen. Barack Obama’s (D-Ill.) presidential candidacy. “As a whip, I can tell you time and again, he’s been there when we’ve needed him.”
Lieberman is a hawkish leftie. Zell Miller was a truly moderate-to-conservative Democrat, as one can tell from reading his book A National Party No More: The Conscience of a Conservative Democrat, and quotes like, "Secular socialism, heavy taxes, big spending, weak defense, limitless lawsuits and heavy regulation — that pack of beagles hasn't caught a rabbit in the South or Midwest in years".
I appreciate Lieberman's support of the GWOT, and it does serve as a template for one's ability to divorce national security issues from the typical partisan spectrum of domestic issues. But on those domestic issues Lieberman is the polar opposite from what the Republican base is looking for. Lieberman is not able to make the case as Zell Miller could on the difference between moderate liberalism and progressive totalitarianism embraced by both Obama and Clinton.
The other important issue is that McCain may have a bigger problem nailing down the right wing of the party rather than moderates and independents. Lieberman does not help the perception that McCain is willing to sell his partisans down the river for a little bit of media support and attention as a "maverick".
And just what is Lieberman selling to the public audience? An unpopular war. He'd better give a damned good speech or he'll do more harm than good.