Here are two graphs representing the distribution of 2012 US House and Senate congressional candidate ideological positions. Higher (more rightward) scores are more conservative, lower (more leftward) scores are more liberal. Click on the plots for higher resolution versions:
A couple of things can be seen clearly from these two pictures:
- There are two distinct distributions of scores, representing the two political parties. They are distinct; or, in other words, the parties are ideologically polarized. Democrats are liberal, and Republicans are conservative.
- There is a significant amount of overlap between the party bell curves. That is, there are plenty of conservative Democrats who are more conservative than a number of liberal Republicans (and vice versa). Even in an age of polarization, the candidate pool is not completely divided, unlike Congress in recent years. This replicates a finding about the Congress of the mid 90s by Stephen Ansolabehere, Jim Snyder, and Charles Stewart from over a decade ago.
- On average, Senate candidates are slightly more centrist than House candidates. This makes sense given the larger, more heterogeneous states that they seek to represent, relative to the smaller and more extremist House districts.
- It appears the candidate pool of the parties in 2012 is roughly symmetrically polarized.
- These scores are based on candidate positions expressed in survey responses, campaign statements, web sites, etc., as compiled by Project Vote Smart.
- They represent 722 House candidates from 419 districts and 64 Senate candidates from 33 states with elections this year. Not all candidates were scored because of a lack of data, but it’s a small number in that position.
- I have jointly classified all candidates into a common space, which simply means that House and Senate scores are comparable.
- More details about how I generated these scores can be found in a companion post that I wrote to keep this one more lean.
- The underlying scores are preliminary and subject to change, but I’m making them available to anyone interested in the name of transparency in another companion post here.
- You can find out more about my research on legislative ideology here.