Guest Pollster | November 11, 2006
Topics: 2006 , The 2006 Race
Today's Guest Pollster Corner Contribution comes from Simon Jackman of Stanford University, who takes a closer look at Tuesday's Senate election results.
Two interesting questions to ask after Tuesday's election are (1) Were the six defeated Republican senators particularly "out of step" with their respective states?; (2) What will be the effect of the Democratic pickups on the look of the new, 100th Senate?
To answer this question I first assigned a liberal-to-conservative voting score to each senator based on an analysis of the 530 non-unanimous roll call votes cast in the 109th Senate. The resulting scores are scaled to have mean zero and standard deviation 1, with lower (negative) scores reflecting a more liberal voting history, and positive scores reflecting a more conservative voting history (the details of this scoring procedure appear in my 2004 article with Josh Clinton and Doug Rivers in the American Political Science Review. A familiar story results, with Democrats on the left, Republicans on the right, with virtually zero no overlap between the parties. Lincoln Chafee is estimated to be the most liberal Republican with a voting score of about zero, while Ben Nelson (NE) is the most conservative Democrat (again, with a voting score close to zero). The usual suspects anchor the extremes of both parties: Barbara Boxer (CA) and Ted Kennedy (MA) for the Democrats (scores of -1.9), and Inhofe (OK) and Demint (SC) for the Republicans (scores of 1.3).
To gauge each state's political complexion, I use a simple and convenient proxy: Bush's share of the 2004 presidential vote in each state, which ranges from a high of 71.5% in Utah, to a low of 36.8% in Massachusetts, with a median of 52.7% (bracketed by Florida's 52.1% and Missouri's 53.3%).
The graph below shows a scatter-plot of voting score against 2004 Bush vote. Each point corresponds to a senator (red for Republicans, blue for Democrats, with senators running for re-election given a heavier shading), with 2004 Bush vote on the horizontal axis, and the roll call voting score on the vertical axis (higher is more conservative, lower is more liberal). The gray line is a regression fit to the data, not to be taken too seriously, but rather more as a rough guide as to how "out of step" the senator may or may not be. Republicans running for re-election are all numbered: Republican senators losing their seats are numbered 1 through 6, the other Republican senators who were re-elected are numbered 7 through 14. Chafee (RI), Santorum (PA) and Allen (VA) seem to be the only Republican losers who are obvious candidates for a "out of step" with their state kind of story (along the lines proposed by Canes-Wrone, Brady and Cogan in a 2002 article in the American Political Science Review, lying relatively distant from the regression line. DeWine (OH) seems to have been caught in what was an extremely difficult election for Republicans in Ohio, and neither Talent (MO) nor Burns (MT) appear to have been particularly "out of step". And keep in mind that there are several Republican senators just as apparently "out of step" as Santorum or Chafee who did not lose their seats: e.g., Jon Kyl (AZ), who faced no Democratic opposition in 2000, but won 53-44 in 2006; or John Ensign (NV), who by almost identical margins in both 2000 and 2006.
It is interesting to speculate on shape of the new, 110th Senate. Chafee goes, replaced by a Democrat, leaving the Maine senators (Olympia Snowe, re-elected with a 74-21 margin in 2006, and Susan Collins) as the most moderate Republicans. It remains to be seen just how liberal or moderate the new Democrats will be. Given their states and the narrow margins with which they are projected to win, it is tough to imagine Webb (D-VA) or Tester (D-MT) being particularly liberal, perhaps voting more like relatively conservative Democrats from the plain states (e.g., Nelson, NE; Conrad and Dorgan from ND) or the other Montana senator (Baucus).