Whenever a Democratic member of Congress is running for election, the most common line of attack by Republicans is to label that Representative or Senator as a “hardcore liberal,” or “one of the most liberal members of Congress.” In 2004, Senator John Kerry was unsurprisingly labeled as the “most liberal Senator” by the RNC, and in 2008 the “most liberal Senator” label was directed toward Barack Obama. These declarations are directed against different members of Congress as needs arise, often without an objective basis of measurement; senators and representatives are picked for the label first, and then legislative records are scoured through to justify the label after the fact.

Here at That’s My Congress, we’ve been working in the opposite direction, keeping track of members of Congress throughout 2009. Our legislative scorecards for the House and Senate have not been pieced together by identifying the actions of legislators we consider to be liberal, then identifying legislation that they support. Rather, we assembled the scorecards by identifying liberal legislation based on its substance, regardless of which legislators had lent their support to it. Further, we not only track vote history but also the history of legislative cosponsorships: the formal declarations of support for a bill that help build momentum behind a bill before it ever comes to the floor for a vote. Our measurements track members of Congress on the actual work that they do in voting and cosponsoring, not just on their political personalities. We measure the percentage of possible liberal policy actions taken by a member of Congress (on a 0-100 scale), and also keep track of the percentage of possible conservative policy actions taken by that member (also on a 0-100 scale). By subtracting a member’s conservative action score from their liberal action score, we arrive at a single Net Congressional Score for each member of Congress.

Because our tracking is based on actual legislative behavior and not on the basis of personality, our list of the most liberal members of Congress in 2009 contains some surprises by absence. If you think Barbara Boxer, John Kerry, Dennis Kucinich or Barbara Lee belongs on that list, think again. In 2009, they played second-fiddle to other Representatives and Senators who were more consistent in their support for liberal policymaking.

The Five Most Liberal Members of the House of Representatives in 2009 are:

1. Bob Filner of California’s District 51. Filner’s Net Congressional Score for 2009: 78.

2. Maurice Hinchey of New York District 22. Hinchey’s Net Congressional Score for 2009: 75.

3. Janice Schakowsky of Illinois District 9. Schakowsky’s Net Congressional Score for 2009: 72.

4. Raul Grijalva of Arizona District 7. Grijalva’s Net Congressional Score: 68.

5. James McGovern of Massachusetts District 3. McGovern’s Net Congressional Score: 68.

The Five Most Liberal Members of the U.S. Senate in 2009 are:

1. Jeff Merkley of Oregon. Merkley’s Net Congressional Score for 2009: 64.

2. Russ Feingold of Wisconsin. Feingold’s Net Congressional Score for 2009: 64.

3. Dick Durbin of Illinois. Durbin’s Net Congressional Score for 2009: 59.

4. Sheldon Whitehouse of Rhode Island. Whitehouse’s Net Congressional Score: 59.

5. Bernie Sanders of Vermont. Sanders’ Net Congressional Score: 59.

In neither house of Congress are there any legislators who would qualify as “superliberals,” supporting a very high percentage of liberal legislation and opposing a very high percentage of conservative legislation. By our tracking of support for bills in the House and Senate in 2009, even the most ardent supporters of liberal policy are not that ardent. These 10 legislators are rather the most liberal among a small set of congressional moderates.