Perhaps the most puzzling phenomenon of the Democratic primary campaign was the frequently heard argument that the candidate of Mark Penn would be the one most likely to advance a bold progressive policy agenda and stick to it. I, myself, am quite happy that Penn will not be advising the next President.
One thing to add to Matt’s broader point is that 1994 was the culmination of the Republican realignment in the South that was made inevitable by the Johnson administration. It won’t happen again to remotely the same extent in 2010 because, er, it’s already happened; there aren’t a lot of easy seats held by nominal Democrats in the south for the Republicans to pick off. To argue for a timorous agenda based in 1994 would be silly; the Dems were going to lose seats then no matter what, and there’s no reason to believe that had Clinton been (even more) centrist this could have been avoided.