PELOSI VS. HASTERT. In his New York Times web column, Carl Hulse argues that there is a stark contrast between the leadership style of Nancy Pelosi and that of her predecessor Dennis Hastert in that Pelosi seems to have abandoned Hastert's "majority of the majority" doctrine, where only bills that had majority support from the leader's party are pushed. Pelosi broke with that notion in bringing the Iraq supplemental bill to passage. However, that's Hulse's only example. I think the war supplemental has to be thought of as fairly sui generis, not merely given the issue at hand but also the fact that disputes over war policy play out in the American political context as fights over "must-pass" funding bills for troops and personnel on the ground. And the next looming test case that Hulse mentions, on trade, may fail to materialize -- liberals actually managed to get most of what they wanted in terms of standards and concessions included in the pending trade deals with Peru and Panama, and thus it seems likely a majority of the Democratic majority in the House will support them.
Generally speaking, while it's certainly true that Pelosi emphasizes in public comments how she differs from the old Republican leadership in her approach and disavows the Hastert doctrine, it's safe to say that the increased polarization and party cohesion that constituted the central story of American congressional politics in the last few decades have continued apace under the Democrats. (Which is a good thing.) Divided government may explain at least some of the discrepancy we might see, since there's still a president of the opposite party around competing to set the agenda and put issues before Congress that might divide the congressional majority.