ABSTRACT
Thomas Kuhn argues that paradigms are important because they direct inquiries to normal science or analyses that work within a set of questions provided by the paradigm. Four indicators were presented from 1974 to 1990 about the fortunes of incumbents: the percentage of safe outcomes, the sophomore surge, and the average percentage of the vote received by all incumbents running for reelection, and the retirement slump. The focus on a growing incumbency effect began with the research that concluded that incumbents were doing better. This evidence prompted scholars to turn their attention to trying to explain the incumbency effect. Although there was a consensus of a growing incumbency effect, there were some concerns about whether the increase was being measured properly or precisely. That consensus then allowed a stream of research that worked within the puzzle of "the vanishing marginals" in an effort to explain why it was happening.
