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Report

Redistricting and Congressional Control: A First Look

  • Sundeep Iyer
  • Keesha Gaskins
Published: October 25, 2012

In Amer­ica’s deeply divided polit­ical climate, even small changes to district bound­ar­ies can determ­ine which party controls Congress. The outcome of redis­trict­ing can make the differ­ence between which policies are adop­ted and which ones are ignored — not just in 2013, but for the next decade. This prelim­in­ary analysis focuses on who drew the lines follow­ing the 2010 Census — legis­latures, commis­sions, or courts — and how that process could affect elect­oral compet­it­ive­ness and the partisan balance of power in Congress in the upcom­ing elec­tion. Many elec­tion contests are decided not on Elec­tion Day, but months and years before, when states redraw their districts. 

 

In Amer­ica’s deeply divided polit­ical climate, even small changes to district bound­ar­ies can determ­ine which party controls Congress. The outcome of redis­trict­ing can make the differ­ence between which policies are adop­ted and which ones are ignored — not just in 2013, but for the next decade. This prelim­in­ary analysis focuses on who drew the lines follow­ing the 2010 Census — legis­latures, commis­sions, or courts — and how that process could affect elect­oral compet­it­ive­ness and the partisan balance of power in Congress in the upcom­ing elec­tion. Many elec­tion contests are decided not on Elec­tion Day, but months and years before, when states redraw their districts. 

 


 

Down­load the Report (PDF)

Read the Exec­ut­ive Summary

See the Inter­act­ive Map

Over­view: Before and After Redis­trict­ing

View the Report


Exec­ut­ive Summary

Follow­ing the 2010 Census, states redrew Congres­sional districts across the coun­try. In Amer­ica’s deeply divided polit­ical climate, even small changes to district bound­ar­ies can determ­ine which party controls Congress. The outcome of redis­trict­ing can make the differ­ence between which policies are adop­ted and which ones are ignored — not just in 2013, but for the next decade. But redis­trict­ing is not just consequen­tial for partisan control. It also affects how communit­ies are repres­en­ted and determ­ines whether legis­lat­ors are respons­ive to the citizens they repres­ent.

What has happened in this redis­trict­ing cycle? What will be the likely consequences? Of course, it is too early to say for sure — the votes have not been coun­ted. But it is not too early to make some prelim­in­ary assess­ments. This study — a prologue to a more extens­ive analysis forth­com­ing in the spring — features our initial analysis of the 2010 congres­sional redis­trict­ing cycle. It focuses on the likely impact of redis­trict­ing on the partisan balance of power in Congress.
Based on our prelim­in­ary analysis, it is clear that:

  • Repub­lic­ans were the clear winners of the 2010 redis­trict­ing cycle. Compared to the current partisan makeup of Congress, the net effect of redis­trict­ing was roughly a “wash.” However, before redis­trict­ing, Repub­lic­ans were not in posi­tion to main­tain long-term control of several seats they won in the 2010 elec­tion. During redis­trict­ing, Repub­lican-controlled legis­latures shored up many of their recent gains: The GOP may now be in posi­tion to main­tain long-term control of about 11 more seats than they would have under the pre-redis­trict­ing district lines. As a result, Demo­crats will find it harder to gain the 25 seats needed to take control of the House in 2012.
  • Demo­crats and Repub­lic­ans used redis­trict­ing to their polit­ical advant­age. Where Repub­lic­ans controlled redis­trict­ing, they may now be in posi­tion to win nine Congres­sional seats currently repres­en­ted by Demo­crats. Demo­crats countered some of these gains where they controlled the process, but Repub­lic­ans redrew the lines for four times as many Congres­sional seats as Demo­crats.

Many elec­tion contests are decided not on Elec­tion Day, but months and years before, when states redraw their districts. Both parties use redis­trict­ing to tilt the elect­oral terrain to achieve specific polit­ical object­ives. This polit­ical games­man­ship brings with it import­ant long-term elect­oral and policy consequences for voters.

Nonethe­less, recent reforms in some states have taken redis­trict­ing out of partisan hands — or, at the very least, may have reduced the abil­ity of partis­ans to manip­u­late the process to their advant­age. For example, Cali­for­ni­a’s new redis­trict­ing commis­sion dismantled several incum­bent-protect­ing gerry­manders, redu­cing the number of safe seats in the state by nine. Mean­while, Flor­ida, where Repub­lican line-draw­ers were required to comply with the state’s new “Fair Redis­trict­ing” criteria, is the only state where Repub­lican state legis­lat­ors drew new Congres­sional districts that may have actu­ally increased the oppos­ing party’s polit­ical power.

Of course, it is far too early to draw conclu­sions about what effects these reforms and others have had. This report is the start­ing point for the Bren­nan Center’s ongo­ing assess­ment of redis­trict­ing and its effects on citizen repres­ent­a­tion. The analysis in this report is limited to the find­ings from the most recent redis­trict­ing cycle based on avail­able data on partisan voting patterns. This report does not address the fair­ness of district bound­ar­ies, nor does it explore whether communit­ies of interest are effect­ively repres­en­ted in the new districts. The analysis also does not draw any causal links between who controlled redis­trict­ing and the even­tual outcomes of the elec­tion.

Follow­ing the 2012 elec­tion, the Bren­nan Center will exam­ine other aspects of redis­trict­ing, includ­ing its effect on minor­ity repres­ent­a­tion and the fair­ness of the process, among others. That broader assess­ment will describe in greater detail the lessons learned from the 2010 redis­trict­ing cycle.


Inter­act­ive Map

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This inter­act­ive map shows the Bren­nan Center’s district compet­it­ive­ness ratings for all 435 Congres­sional districts. For each district, the map also includes estim­ated partisan voting results from the 2008 Pres­id­en­tial elec­tion, as well as the 2012 district ratings from The Cook Polit­ical Report, The Rothen­berg Polit­ical Report, and Sabato’s Crys­tal Ball. Unlike the district ratings developed by these news­let­ters, the Bren­nan Center’s district ratings do not take into account elec­tion-specific factors such as candid­ate popular­ity and campaign spend­ing that could affect a partic­u­lar elec­tion result. Rather, the Bren­nan Center’s ratings are based only on the partisan voting history in each district. The ratings are explained in detail in Redis­trict­ing and Congres­sional Control: A First Look.    


Over­view: Before and After Redis­trict­ing

Table 1: Repub­lican and Demo­cratic Seats in Congress, before and after redis­trict­ing. The table shows the number of Repub­lican and Demo­cratic seats in Congress based on the current partisan makeup of Congress and based on compet­it­ive­ness ratings.



Redis­trict­ing and Congres­sional Control: A First Look