American Politics Research
2022, Vol. 50(6) 735–742
© The Author(s) 2022
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Dueling Incumbent House Elections,
H. Benjamin Ashton
, Michael H. Crespin
, and Seth C. McKee
Throughout American history some members of Congress are beset with the unfortunate predicament of facing a fellow incumbent
in their bids for reelection. One culprit is responsible for these atypical contests: redistricting. Using district and sub-district level data,
this research note provides the first systematic coverage of all dueling incumbent general election U.S. House races from 1843 to
2018. We chronicle and analyze when we expect to see dueling incumbent races, the ability of parties to target out-party incumbents,
and the electoral value of previously represented constituents for incumbents in reconfigured districts. Although incumbent duels are
uncommon, they comprise a substantial number of incumbent general election defeats in contests following redistricting.
house elections, dueling incumbents, redistricting, electoral retrenchment
In this research note we provide the first comprehensive
examination of the 73 dueling incumbent (incumbent vs.
incumbent) general election contests in the U.S. House of
Representatives from 1843 to 2018.
Although these types of
races are infrequent, since 1952 they account for 22% of
incumbent defeats in general elections held immediately after
a decennial redistricting.
In this exploratory and primarily
descriptive account we consider: (1) the determinants of the
emergence of dueling incumbent races such as redistricting,
reapportionment, and partisan targeting, (2) the role of par-
tisan mapmakers in eliminating out-party incumbents when
redistricting occurs, and (3) evaluate the support incumbents
garner among the voters they retain following a redistricting.
Dueling Incumbent Races, 1843–2018
Dueling incumbent races are seldom mentioned in extant lit-
erature on congressional elections
, and the few previous ac-
counts characterized their existence as a “failure”of redistricting
strategies that come with (by definition) a high rate of incumbent
defeat (e.g., Bullock, 1975;Bullock, 2010). We expect dueling
incumbent races to primarily manifest in two instances, as
described in Figure 1. First, redistricting is a causal factor for
observing incumbent versus incumbent contests. Changing
district lines forces incumbents to decide where to run for re-
election and all 73 of our dueling incumbent contests take place
in the confines of redrawn congressional boundaries.
Next, we expect to see more duels in states that lose a
district, an event we call electoral retrenchment. When this
occurs, the number of incumbents is greater than the number
of districts so we should observe a duel if all incumbents
decide to run for reelection. Our data support this hypothesis
with 63% of our cases in states experiencing electoral re-
trenchment. The rest of the dueling incumbent matchups
happened when states either gained a seat (10%) or retained
the same number of seats following reapportionment (27%).
We also expect to observe more duels when one party draws
district lines since they can “target”the out-party by drawing
boundaries unfavorable to an incumbent of that party. Our
data show that 68% of duels occur when one party controls
redistricting. The remaining contests occur in comparatively
less partisan settings, including when district boundaries are
reconfigured by the courts, commissions, or via a divided
state government (e.g., different parties in control of the
legislative chambers and/or the governorship).
Figure 2 presents all 73 contests in our dataset. Twenty-
eight different states had at least one dueling incumbent
contest. Populous states consistently losing districts have the most
duels: Ohio with 10, followed by Pennsylvania (8), New York (5),
and then several states with 4. Forty-one dueling incumbent races
occurred in states losing at least one seat through reapportionment.
Another five contests operated under the condition of electoral
retrenchment because an at-large seat (or seats) was subsequently
Department of Political Science, Carl Albert Congressional Research and
Studies Center, University of Oklahoma, Norman, OK, USA
Department of Political Science, Oklahoma State University, Stillwater, OK,
Seth C. McKee, Department of Political Science, Oklahoma State University,
Stillwater, OK 74078, USA.