Dueling Incumbent House Elections, 1843-2018

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.