National Journal has released their ratings of members of Congress. Some interesting results:

James Inhofe just edges Jim DeMint as the most conservative senator. Sherrod Brown of Ohio, Roland Burris of Illinois, Ben Cardin of Maryland, and Jack Reed and Sheldon Whitehouse of Rhode Island are tied for the most liberal. All Democrats, obviously. According to National Journal, there are 37 Democratic senators more liberal than the self-identified socialist Bernie Sanders of Vermont. The Senate’s oddest couple is Harry Reid and John Ensign of Nevada, who have about 70 senators in the ideological space between them.

There are six Republicans tied for most conservative in the House: Trent Franks and John Shadegg of Arizona, Randy Neugebauer, Pete Olson, and Mac Thornberry of Texas, and Doug Lamborn of Colorado.

One interesting thing is the lack of ideological diversity in Congress. Economic liberals are also social liberals; economic conservatives are also social conservatives. The following graph shows the ratings for the entire House, with social conservatism (100 means being most conservative) on the vertical axis and economic conservatism on the horizontal axis. 

There is a bit more diversity among Democrats (i.e. there is more dispersion in the bottom left corner), probably in part because there are more of them and more of them in toss-up seats. The Republicans are very homogeneous, especially among the most conservative members. But note that there are no House members toward the upper left or bottom right corners, or even close to them. Even Ron Paul, considered something of a libertarian outlier, is toward the middle of the Republican pack both economically and socially. The two representatives who come closest to breaking the ideological pattern are Dennis Kucinich of Ohio and Jared Polis of Colorado, both of whom earned a zero on social conservatism but scored very close to 50 on economic conservatism.

Obviously these rankings are limited in key ways. But it is remarkable that while there are voters who are economically conservative but socially liberal and vice versa, there aren’t representatives who vote that way.