Partisan and Incumbent Effects in State Legislative Redistricting

The effects of reapportionment on partisan balance and on the reelection of incumbents should be expected to differ, depending on whether the reapportionment process was effectively controlled by one party or was bipartisan or nonpartisan. These hypotheses are tested in 15 state legislatures for the post-1980 redistricting. Partisan effects are most likely to occur where the process is highly partisan. Even then, however, the partisan gains are likely to be short term and to dissipate after two or three elections. Incumbents who run appear more likely to get reelected in the years following an election, whether the process was controlled by one party or was bipartisan.