Search

Competition in U.S. House elections has been declining for more than 50 years and the 2002 and 2004 House elections were the least competitive of the postwar era. This paper tests three hypotheses that attempt to explain the decline in competition in House elections: the redistricting hypothesis, the partisan polarization hypothesis, and the incumbency hypothesis. We find strong support for both the partisan polarization hypothesis and the incumbency hypothesis but no support for the redistricting hypothesis. Since the 1970s there has been a substantial increase in the number of House districts that are relatively safe for one party and a substantial decrease in the number of marginal districts. However, this shift has not been caused by redistricting but by demographic change and ideological realignment within the electorate. Moreover, even in the remaining marginal districts only a small minority of House races are competitive. The main explanation for the lack of competition even in marginal districts appears to be the inability of challengers to compete financially with incumbents. [ABSTRACT FROM AUTHOR]