Every year, the National Journal rates the US Senate and the House members on ideology, and then tells us who are the most liberal and conservative in each body. Here, we’ll look at who were the most liberal senators last year and compare it to the most liberal senators in 2011.

Generally in this list, we find that a senator’s rankings are based upon four different things: their political party, their own personal ideology, their state’s ideology, and when they next have to face the voters. As could be expected, the most liberal senators come from the most liberal states and usually, as their re-election looms closer, they tend to move toward the center.Obviously, each of the most liberal senators are Democrats; as the Senate has grown more dichotomous, and the political parties have become more national, in recent years all Democrats are more liberal than all Republicans.

Here are the top ten liberals in the Senate based upon their 2012 voting records:

1. (tie) Blumenthal – CT
Udall – NM
3. (tie) Durbin – IL
Franken – MN
5. Murray – WA
6. Lautenberg – NJ
7. (tie) Brown – OH
Cardin – MD
Reid – NV
10. Boxer – CA

A couple of reflections on this list:
* Either Udall doesn’t represent the values of New Mexican voters or that state is moving left at a pretty rapid rate.
* Al Franken is as liberal as everyone thinks that he is.
* Sherrod Brown is way more liberal than Ohio. He’s always going to have a tough re-election fight.
* Barbara Boxer in 10th place? What’s up with that?

Here are the senators who dropped off the list:

* Gillebrand (NY) was tied for first last year and now is nowhere to be found. She ran for re-election in November.
* Merkley (OR) was tied for first last year and is off the list. He is running for re-election next year.
* Akaka (HI) ran for re-election in November.
* Harkin (IA) was tied for fifth place; he is running for re-election next year.
* Mikulski (MD) was tied for fifth place; maybe she is mellowing.