Below we plot the first dimension DW-NOMINATE Common Space scores of the presidents in the post-war period, which we refer to as the “presidential square wave” due to its shape. An ideological score is estimated for each president throughout the entirety of their tenure in office by scaling their “votes” on a subset of roll call on which they announce a position (measured using CQ Presidential Support Scores). Negative scores indicate greater liberalism and positive scores indicate greater conservatism. The presidential scores are directly comparable across time and with members of Congress.
Very little has changed from the last presidential square wave. President Obama fits the spatial model estimated by DW-NOMINATE extremely well, with over 95% of his “votes” correctly classified. Obama has moved very slightly leftward (-0.363) and is now just to the left of LBJ (-0.346) and right of Truman (-0.368), though this trio is virtually ideologically indistinguishable. President Eisenhower is the most moderate president (0.302) of the post-war era.
Among members of the 113th Congress, President Obama is very ideologically close to Representatives John Garamendi (D-CA) [-0.362], Marcy Kaptur (D-OH) [-0.365], and Carol Shea-Porter (D-NH) [-0.354] in the House, and Senators Patty Murray (D-WA) [-0.367] and Mark Udall (D-CO) [-0.369] in the Senate.