The Watershed Congress and Theory Development
In November 1994, the Republican party gained control of both chambers of the U.S. Congress for the first time in forty years. This remarkable event captured the attention of the nation, and offered political scientists new conditions under which to reassess the validity of dominant theories and models of legislative behavior and the evolution of the congressional institution (Fenno 1997 1; Sinclair 1997). During the post-World War II era, legislative theory shifted from a sociological foundation to a psychological base. In the sociological model, the social backgrounds of individual members of Congress were thought to offer the best explanation of the actions of members of Congress. By contrast, the psychological model worked from the conception that individuals are less the highly predictable product of their early environment and social status than they are a reflection of their needs, interests, values, perceptions, and goals. This is not to say that the psychological model entirely discounted the sociological model. Instead, it repositioned the sociological model as conditionally helpful but less able to explain, predict, and offer lasting generalizations about legislative behavior than the psychological model.