Stirling Newberry’s analysis of the progressive pedigree of the likely new Senate -- "The Coming Progressive Plurality" -- is brilliant research, and of course it should go without saying that a Democratic majority is not the same as a majority for progressive policies. After all, the last sustained Democratic majority in the Senate -- 1986-1994 -- incorporated characters like Richard Shelby, who not only were more at home in the G.O.P., but on the far-right fringes of that party. It's also important to note that some economic liberals are social conservatives, and so forth.

For the most part, I think he’s got these characters’ basic instincts figured out, with the exception that I do not understand the veneration of Jim Webb -- a perfectly great candidate, emblematic of the disenchantment of a certain kind of generally conservative person, but I think most likely to be a Bob Kerrey-type in the Senate (idiosyncratic, impulsive, non-ideological -- I happen to like Bob Kerrey, so I don't think this is so bad) -- and the disparagement of Ben Cardin, who gets zeros from Newberry on all but the grab-bag category of "civil" liberalism. Cardin has obviously been a lackluster candidate, but he’s been a very reliable moderate-progressive member of the Ways and Means Committee, and I would bet that when it comes time for the massive tax overhaul that we’ll need for any kind of progressive vision, he will be a key workhorse.

But my big objection to Newberry’s analysis is that shaping a real progressive or liberal vision for the years to come is not simply a matter of scoring individual legislators as liberal or conservative.

On a few of the social issues, it is, e.g. Bob Casey is anti-abortion and is going to stay that way. Votes on certain issues and nominations are predictable along those lines. 

But politicians are malleable, indeed, they are supposed to be malleable and responsive. And they do more than vote. The agenda that comes out of a given structure of power is shaped only in part by the configuration of votes in the body. More important than how they will vote are the questions of what they will vote on, how the agenda will be shaped, and how they will present themselves. And also, how will they position themselves in relation to the other centers of power in Washington -- the White House and the permanent government of mostly corporate lobbyists. Those are the big questions coming out of today's vote, assuming Democrats win control of at least one chamber, because they will determine what's possible. There are scenarios under which someone like Sherrod Brown is at the center of a progressive resurgence, others in which he becomes a relatively marginal figure.

A few months ago, Republican former Rep. Vin Weber told me that the most productive time for conservative Republicans was the last two years of the Carter administration, after the Republicans won 15 seats in the 1978 elections. Both the Reagan Revolution and the later Gingrich episode have their seeds in that era, when the Kemp-Roth tax cut was fashioned, David Stockman developed his ideas about the politics of entitlement spending, and a lot of mainstream Republicans, becoming enamored of the conservative phrase, "ideas have consequences," suddenly became much more ideological. The whole sense of what was possible changed completely between 1978 and 1981, and Reagan would have been a much weaker and different president if his party had not used that time on the cusp of power so well.

It’s not their own fault -- the current crisis does not give one much time for reflection on ideas and their consequences -- but I can’t say that Democrats have used their time out of power nearly as well. But if they can use the next two years, a time in which they have the momentum to develop and establish a national agenda but not the power to govern, as well as the conservatives used the late 1970s, then all the potential that Stirling recognizes will be realized.