Looking at voting records over the last year, National Journal has the 15 most conservative and liberal U.S. House and Senate members.
In the House, the top three most conservative are: Steve Chabot (R-Ohio), George Holding (R-N.C.) and Kenny Marchant (R-Texas)
Most conservative in the Senate: James Risch (R-Idaho), Michael Enzi (R-Wyo.) and Tim Scott (R-S.C.)
In the House, the top three most liberal are: Judy Chu (D-Calif.), Keith Ellison (D-Minn.) and Donna Edwards (D-Md.)
Most liberal in the Senate: Brian Schatz (D-Hawaii), Chuck Schumer (D-N.Y.) and Chris Murphy (D-Conn.)