Getty Images Washington Post In this November 2, 2018 file photo, Democrat Alexandria Ocasio-Cortez speaks in New York City.
WASHINGTON — States wielding gerrymandered election maps have gotten more popular since the 2010 congressional map redraw, even as the Republicans have sought to protect themselves from challenges, according to a new analysis by the Brookings Institution.
This combination of Republican congressional incumbents at the top of the ballot and gerrymandered maps is not unlike the dynamic that helped enable Donald Trump to win the presidency and the Republicans to retain control of the House.
According to the Brookings analysis, state lawmakers approved 13 new districts from 2000 to 2016 that created larger majorities for Democrats. Yet from 2010 to 2016, for the entire partisan tilt, Democrats outpaced Republicans in U.S. House elections, winning 32 seats compared to the Republicans’ 16.
The report is drawn from measures that identify areas that Democrats are likely to win by large margins. The mapmakers select states that have small number of active Democratic voters and large numbers of Republican voters to minimize the effects of gerrymandering and distribute the new votes equally.
Four states — Massachusetts, New York, Oregon and Minnesota — have created more compact districts while leaving some voters clustered together. Every other state has produced far more compact districts, significantly diminishing the edge incumbent House members have to protect themselves from challengers.
After the 2010 reapportionment, Republicans won an astonishing 63 percent of the House seats, mainly because of new maps that tilted the playing field in their favor. Democrats had only 22 percent. Partisan voting patterns are more fickle than party control of Congress, so even in districts in which Democrats had a stronger shot of winning, the mapmakers bent the boundaries to help Republicans survive.
The Brookings report, titled “How Gerrymandering Became a Winning Strategy,” notes that while the redistricting results after 2010 show Republicans are winning this strategy, Democrats have also come a long way in their ability to target their political vote.
“Most polarization in American politics has occurred in legislatures, not the president’s office,” said Richard D. Nixon Professor of Public Policy, James H. K. Downie Jr., who led the study. “But even in legislative elections, polarization has become more strongly associated with clustering, gerrymandering and a Democratic advantage for long electoral runs.”
The Associated Press contributed to this report.