The Unidimensional Congress, 1919-84

Abstract

A simple unidimensional spatial model provides a highly accurate description of roll call voting in the United States Congress. Moreover, the dimension exhibits remarkable temporal stability. Today's liberal-conservative lineup basically prolongs the major political axis that existed both after World War I and after the Great Depression. These theses are argued on the basis of a statistical analysis of, essentially, every recorded roll call vote in the House and in the Senate in the years 1919-1984.