The Effects of Redistricting on Incumbents

We analyze the effects of redistricting on the electoral fortunes of incumbent legislators, using voting data on U.S. congressional districts, state legislative districts, and statewide races. We find little evidence that redistricting helps incumbents in U.S. legislative elections. If anything, redrawing district lines reduces the average vote margin of those in districted o±ces compared with o±ces that are not districted, reduces electoral security, and increases turnover in the legislature