The end of midterm decline? Congressional elections in historical perspective

Variations in the loss of seats in the House of Representatives by the president's party in midterm elections between 1854 and 1998 are analyzed from a historical perspective. Whereas in the latter three-fourths of the nineteenth century the president's party lost, on average, 22% of its share of House seats, in the twentieth century the average loss was 13%. Using district-level data, the author attributes the problematization of "midterm decline" to the growing power of incumbency (a consequence of the development of the Australian ballot), the decline in the number of partisanly competitive districts in open-seat elections, and the limitation, since 1912, of the size of the US. House of Representatives.