Political Arithmetik has a couple of interesting pieces on the upcoming ideological shifts in the 110th Congress. First, Charles Franklin produces a graph showing the ideological shift among committee chairs:



Apart from the science committee, where apparently a conservative Democrat is replacing a liberal Republican, every single committee appears to be experiencing a strong leftward shift. This even goes for the Agriculture committee, where conservative Democrat Collin Peterson will be chair. Then again, since the National Journal ideological rankings that Franklin uses describe a given Representative's entire voting record, these score may not be all that relevant. For example, the Democrat chairing the science committee could be quite liberal when it comes to science, but generally conservative overall. At the same time, the energy and commerce committee could be moderate to conservative on those issues, while s/he is overall quite progressive. In other words, to understand the ideological shift, what matters most is how someone votes when it comes to the given policy area where s/he will have control, not someone's overall voting record.

Next, Franklin looks at the voting records of the 19 Republican incumbents who were defeated, and the one incumbent Democrat who was defeated (Cynthia McKinney). He writes: Republican losses fell along most of the ideological spectrum, but were a bit more common among moderates than among the more conservative members of the party.(...)

Republican incumbents who were defeated for reelection had an average conservatism score of 66.5, while those who won averaged 74.3, a statistically significant difference. (The average for all Republicans in 2005 was 73.2, and the median was 74.4.) So, the Republican caucus in the 110th Congress will be even more conservative than they were in the 109th. Given this, and that bush is still in the White House, I would expect the new Republican caucus to dig in, and serve as a particular nasty and vehement opposition over the next two years. At the same time, their reactionary nature may become even more visible to the entire nation. Expect the vast majority of this Republican caucus to vote against some really popular agenda items, such as investigating Iraq war profiteering, and raising the minimum wage.

I wish that Professor Franklin had looked at more than just the defeated members of each party, and also looked at retirements and resignations. In addition to the twenty Representatives who were defeated for re-election, another two or three dozen are leaving the House at the end of the 109th Congress without being "defeated" as such. To get a better sense of the upcoming ideological shifts, it would be nice to know where those Representatives fit into the overall picture.