Michael Tomasky’s article, “Who Are the Blue Dogs?” in the December 3rd edition of The New York Review of Books is one of the most revelaing pieces yet written on the topic. Tomasky probes the dimensions of the Blue Dogs’ numerical strength in the House, the demographics of their districts and how the numbers play out in their respective regions. He concludes that,

…The Democratic congressional party has become far more ideologically diverse than the Republican one. In theory, and sometimes in practice, this can be a good thing. But it means that Democrats simply can’t act with the kind of unanimity one sees among Republicans. There is too much disagreement within the caucus…
Certainly, Blue Dogs and other rural Democrats can’t vote like Manhattan’s Jerry Nadler. Everyone understands that. But it’s also not entirely clear that one or two controversial votes would endanger many of these legislators.

A good point. Tomasky also provides some interesting observations about the importance of victory margins:

All but a small number of these Democrats won their own races by a greater margin than McCain’s over Obama in the district. Thirty of them beat their GOP opponents by 10 percentage points more than McCain beat Obama. I calculated these numbers in late July, comparing the Democrats’ victory margins to McCain’s, determining each Democrat’s “margin versus McCain”(MVM).[7] Ross, for example, ran unopposed, scoring an MVM of +67. Melancon also ran unopposed, producing an MVM of +76. Herseth Sandlin’s margin was +28, Shuler’s +21. Only eight of the forty-nine had negative margins. Minnick’s, for example, was –25. He and a handful of others have every right to proceed with caution.
But for the vast majority of members of Congress, once you’ve been elected and reelected once or twice, it takes either a pretty big scandal or a rare historical tidal wave (as in 1994) to produce defeat. Members know this—in fact, they typically know exactly how many percentage points a certain vote might cost them at the polls. One begins to suspect that some Blue Dogs don’t really fear losing as much as they fear facing a semicredible opponent and actually having to campaign hard for a change.

Tomasky offers this insight on the topic of what the Blue Dogs really want:

…It is true that they “campaigned on fiscal responsibility,” as the Pelosi spokesman put it after the stimulus vote. What Blue Dogs typically want out of legislative negotiations, one leadership aide told me, is to be able to go back to their districts and say to their voters that they managed to wrest this or that concession out of the more liberal leadership. This aide spoke of “thousands of hours of meetings” with individual legislators seeking to change health care legislation in large ways and small: “If you can’t go back to your district and say, ‘I’ve changed this bill to reflect you voters,’…you have to be able to point to something that you did that made the bill better.”

An important consideration to keep in mind as congressional leaders craft a final bill that can win the support of a broad cross-section of Democrats.