Parker Griffith's defection to the Republican party raises an important question for electioneers: how many more Parker Griffiths are out there? Can Democrats expect another five defections, or, more likely, retirements? The most like answer is that Griffith isn't alone, but he's part of a very endangered species of Southern Democrat.
The important thing to recognize about Parker Griffith's district is that it's part of the "White South". Winning in this district requires the votes of white voters who are significantly less likely to vote for Democrats than typical white voters, and there aren't enough African-Americans in the district to offset the tendencies of the district's white voters. In fact, here's a complete list of Congressmen who, on election day 2008, represent more hostile terrain on this score than Griffith:
- MS-04: Gene Taylor
- LA-06: Don Cazayoux
- TX-22: Nick Lampson
- TX-17: Chet Edwards
- MS-01: Travis Childers
- SC-05: John Spratt
- NC-02: Bob Etheridge
- LA-03: Charlie Melancon
- UT-02: Jim Matheson
- GA-08: Jim Marshall
- AL-05: Bud Cramer (now Parker Griffith)
Two of these Members—Cazayoux and Lampson—lost there seats. A third, Charlie Melancon, is giving up his seat to run for the Senate against Diaper Dave Vitter. The rest of this list is filled with Reps who make Democrats nervous, either because they might retire, or because their voting records are terrible. Now, some of these guys are effective enough that they can probably fend off a real challenger. But even if they can't, this list is pretty small, and only Spratt and Edwards provide a ton of value to the caucus.
Obviously, this isn't an exhaustive list of vulnerable Democrats. But the list of Democrats more vulnerable than Parker Griffith is pretty small. Chris Carney and some of the White South Democrats from Tennessee and Arkansas might be more vulnerable, but only by a small margin. But even including these members, there aren't enough seats here to end the Democrats' majority.