What makes this an interesting prospect is that the next Democratic Congress could very well be the first progressive majority since LBJ's good years. No old school Southern Democrats in the chairmen's seats. If we play our cards right, it could be sustainable--not one of those deals where you need to have a popular President to keep a third of the caucus from bolting at every chill breeze. I think 95% of the Democrats elected to the House and Senate today are truly progressive at heart--even if some of them have to vote CYA right now. The key to our success will be in how we structure our policy offerings to forge a center-left/liberal alliance rather than trying to appease the old center-right vs. moderate/liberal tension, which could never hold under pressure (e.g., 1992-94).
He's right, the Democrats today are a very different congressional party than they were even 12 years ago.