In this post we use Bayesian Aldrich-McKelvey scaling to analyze voters’ perceptions of the ideological positions of Senators and Senate candidates who will be running in close races in 2014 (we also describe the Bayesian Aldrich-McKelvey scaling method in our book Analyzing Spatial Models of Choice and Judgment with R. To do so we use data from the 2012 Cooperative Congressional Election Study (CCES). The 2012 CCES asked respondents to place national figures like President Obama and Mitt Romney (as well as the Democratic/Republican Parties, the Tea Party, and the Supreme Court), their Senators and Representatives on a seven-point ideological scale ranging from extremely liberal to extremely conservative.
Bayesian Aldrich-McKelvey (BAM) scaling corrects for bias in respondents’ placements (for example, when a liberal respondent overstates the conservatism of political figures or vice versa) to create measures of citizens’ ideological perceptions of political figures that are comparable across states and districts. We have previously used BAM to show that raw liberal-conservative self-placement data understates the true level of polarization in the electorate.
Below we plot the BAM estimates of the liberal-conservative positions of incumbents and challengers (if they were included in the 2012 CCES) in selected 2014 Senate races. One of the advantages of using 2012 data is that we can also estimate the positions of Senatorial candidates who were unsuccessful that year; in particular, former Rep. Todd Akin (Missouri) and Richard Mourdock (Indiana). Both lost very winnable races after making controversial statements about abortion and rape. One of the big questions heading into 2014 is whether the Republican Party will again let races slip through their fingers by nominating candidates perceived to be too conservative and out of the mainstream.
According to the BAM estimates, the likely Republican nominees in close races like Arkansas and Louisiana, safer races like Montana and West Virginia, and greater long-shots like Colorado and New Hampshire are all perceived to be more ideologically moderate than the Tea Party in general or Akin and Mourdock specifically. In fact, perceptions of all of these candidates are virtually indistinguishable from those of Mitt Romney, with the exception of former Sen. Scott Brown (R-MA), who is located much closer to the center.
All of the Democrats are perceived to be closer to the center than President Obama, with Sen. Jeanne Shaheen (D-NH) as the most liberal of the group and Sen. Mark Pryor (D-AR) as the most moderate. Interestingly, Sen. Mary Landrieu (D-LA) is perceived to be slightly more liberal than Sen. Kay Hagan (D-NC) and considerably more liberal than Pryor by Louisiana voters. This does not bode well for her in her race for a fourth term. There is also the question of how much these races will be a referendum on the Senators personally rather than on national conditions like the economy, presidential approval, and the Affordable Care Act.
Note: the correlations between the BAM scores and DW-NOMINATE Common Space scores are moderate-high, although the samples size is very small: r = 0.96 overall, r = 0.49 for Democrats, and r = 0.75 for Republicans.