American Prospect editor Michael Tomasky has nailed it. In the May issue, he argues persuasively (and with much useful historical detail) that the party must reclaim its philosophical core: the principle of the common good. Republican screw-ups are handing us good poll numbers, but poll numbers won’t be enough to save the either Democratic party or the country:

What the Democrats still don’t have is a philosophy, a big idea that unites their proposals and converts them from a hodgepodge of narrow and specific fixes into a vision for society. Indeed, the party and the constellation of interests around it don’t even think in philosophical terms and haven’t for quite some time.

Tomasky relates how many liberals lost faith in the common interest in the ’60’s, because of impatience with the slow pace of reform, especially in the face of assaults on progress like the Vietnam War and the assassination of Martin Luther King. But the hodge podge of interest groups that remains does not add up to an inspiring movement, and invites Republican attacks that Democrats lack values, are selfish, etc. The solution is to reclaim the common good:

This, historically, is the moral basis of liberal governance — not justice, not equality, not rights, not diversity, not government, and not even prosperity or opportunity. Liberal governance is about demanding of citizens that they balance self-interest with common interest. Any rank-and-file liberal is a liberal because she or he somehow or another, through reading or experience or both, came to believe in this principle. And every leading Democrat became a Democrat because on some level, she or he believes this, too.

It’s a beautifully developed argument, bringing together strands of thought that have been developing in many different places over many years, and it would serve well as the guide to rebuilding the Democratic Party.