It’s almost the end of this session of Congress, so we’re looking back to see who were the most liberal members. The DW-NOMINATE score was developed by Keith Poole and Howard Rosenthal as a way to determine where legislators voted in relation to each other.
By looking at how each legislator voted on every roll call vote compared to the member’s peers, DW-NOMINATE is able to show how liberal or conservative a Congressman or Senator is.
Over the course of a session, they develop a score based on how they vote compared to their peers. By looking at hundreds of roll call votes and comparing them mathematically, the DW-NOMINATE process is able to figure out where each member sits politically compared to other members.
The closer to -1 a member’s score is, the more liberal they are. The closer to 1 a member’s score is, the more conservative they are. At zero, a member is considered very, very centrist.
On this list, the closer the score is to -1, the more liberal the member is.
Knowing this, Poole is able to rank them in order of partisan tilt based only on how they voted in a single session.
Ellison, who co-chairs the Congressional Progressive Caucus, was the first Muslim ever to be elected to Congress. He also serves on the House Financial Services Committee.
Grijalva, the other co-chair of the Congressional Progressive Caucus, has represented Arizona's 7th district for five terms, and serves on the Committee on Education and the Workforce and the Committee on Natural Resources.
Schakowsky, a seven-term Congresswoman, is the Chief Deputy Whip for the House Democrats, as well as a member of the House Steering and Policy Committee and co-chair of the Seniors Task Force.
Clarke, who represents a central Brooklyn district, has been in Congress for six years, succeeding Rep. Shirley Chisholm, the first black woman to serve in Congress. Clarke sits on the House Homeland Security and Small Business committees.
A veteran California liberal, Stark lost his re-election bid to fellow Democrat Eric Swalwell this year, ending a 40 year career in the House.
Filner declined to run re-election in order to run for Mayor of San Diego. He won that election, and assumed the office Dec. 3, becoming the first Democrat to win the office since 1992.
McDermott has represented Washington's 7th District, which includes Seattle, for 24 years, and is a senior member of the House Ways and Means Committee.
With the retirement of Rep. Barney Frank (D-MA), Waters will become the Ranking Member of the House Financial Services Committee. A 22-year veteran of the House, Waters represents parts of Los Angeles and its surrounding communities.
Conyers has served in Congress since 1965, making him the second-longest serving incumbent in the House. He is currently the Ranking Member of the House Judiciary Committee.
Lee, whose district includes Oakland and other parts of the East Bay area, is entering her eighth term. She is a member of the House Committee on Appropriations and is a former co-chair of the Congressional Progressive Caucus.
Business Insider Emails & Alerts
Site highlights each day to your inbox.