E. J. Dionne Jr. writes that Lieberman should learn the lesson from this primary challenge:

As for this primary, the lesson already is clear: A Democratic Party that has been on defense since the 1980s desperately wants to go on offense. Lamont understands that. If Lieberman is to survive this round, he needs to make clear between now and next Tuesday that he’s gotten the message.

Here is what he believes is the problem with Lieberman:

Lieberman’s core problem was not even his support for the Iraq war. It was his eagerness to challenge the legitimacy of fellow Democrats who have called attention to the administration’s mistakes. Lieberman, confident of Democratic support, seemed to crave the affection of Republicans most of all.
The statement that did more than anything to power this primary challenge was a comment Lieberman made in December.
“It’s time for Democrats who distrust President Bush to acknowledge that he will be the commander in chief for three more critical years,” Lieberman said, “and that in matters of war, we undermine presidential credibility at our nation’s peril.” The implication that there is something wrong with criticizing George W. Bush is unacceptable to most Democrats, who believe that Bush himself has done the most to undermine his own credibility.

So, Lieberman believes that we shouldn’t undermine our war efforts by criticizing the President, that the Democrats should understand that Bush isn’t going anywhere and so they shouldn’t undermine his credibility abroad. And this is wrong to Dionne, not undermining our war efforts is wrong. And he thinks that Lieberman should learn this lesson: we should undermine our war efforts by undermining the credibility of the President. I wonder if Lieberman will take his advice.