I said earlier today that the pattern of party leadership that overreaches is that the rank-and-file up and revolt. I'd like to say "Aha!" at the news that Congressional Progressive Caucus co-chair Rep. Raul Grijalva is upset about ping-pong, but I'm afraid that this is an entirely different phenomenon: a powerless, cranky back-bencher blowing off steam. I haven't blogged about Grijalva before, mainly because he's just not that important, but he seems to get a disproportional share of attention from liberal bloggers, so I'll just say this: if Henry Waxman is happy with the process, then liberals (or progressives, whatever) should be happy. The difference between Nancy Pelosi (who is following Tip O'Neill's lead) and Speakers such as Jim Wright and Newt Gingrich is that Pelosi knows how to keep powerful committee chairs happy.
I'll clarify: it's of course true that there is a clear space to the left of mainstream liberals such as Waxman (and, for that matter, Pelosi). I don't expect the far left to be very happy with what a Democratic Congress and a Democratic president do. And they're certainly entitled to be as vocal as they can about it. That's not really what's going on with the Congressional Progressive Caucus, which as far as I can tell isn't actually promoting different policies in most cases than the rest of the mainstream liberals in the Democratic caucus; they simply are carrying out a policy of reflexively saying "farther left" to whatever the Speaker and the committees can manage to pass. Since everyone knows that their threats are just a bluff (their interests and preferences are pretty much identical to those of the mainstream Dems they complain about), it's hard to get very worked about about their bluster.
By the way, for those who do want to move Congress in a more liberal direction, I'd recommend reading these guys.