Following publication of David Mayhew’s article on the declining number of
marginal districts in elections for the House of Representatives scholars of congressional
elections fixed their attention on identifying the source of incumbents’ electoral
advantages and why the number of marginal districts had decreased (Mayhew, 1970).
Utilizing various data sources and analytic techniques, a long list of suspected causes of
the incumbency advantage were examined. Much of this research concluded that the
incumbency advantage was based on a “personal vote;” that is, a vote based upon the
visibility and high esteem achieved by the officeholder’s engagement in activities
subsidized by the government.
Recent research emphasizes the extent the large margins of victory enjoyed by
incumbents is based upon a partisan rather than a personal advantage (Erikson and
Wright, 2005; Fiorina 2005; Oppenheimer, 2005). The partisan advantage stems from
the fact that incumbents represent districts filled with voters who identify with their party.
If the incumbent derived absolutely no electoral benefit from establishing a personal vote
—or even from ample campaigns funds or a low quality opponent—they would still win
handily given the powerful role partisanship plays in citizens’ vote choice. This research
maintains that the enhanced role of partisanship in the voting decision and decline in the
number of party-competitive districts results in fewer office-holders finding it necessary
to utilize the perquisites of office to achieve a personal vote (Oppenheimer, 2005).
Hence, the incumbency advantaged has declined as a result of the drop in the number of
party-competitive districts in the United States. However, in those districts that remain
party competitive, the incumbency advantage should still be evident.
The research presented here examines whether the importance of incumbency in
the voting decision for House elections has in fact declined and whether a personal vote
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Convention