FiveThirtyEightFiveThirtyEight

PUBLISHED Jan. 25, 2018 at 6:00 AM

The Atlas Of Redistricting

By Aaron BycoffeElla KoezeDavid Wasserman and Julia Wolfe

There’s a lot of complaining about gerrymandering, but what should districts look like? We went back to the drawing board and drew a set of alternative congressional maps for the entire country. Each map has a different goal: One is designed to encourage competitive elections, for example, and another to maximize the number of majority-minority districts. See how changes to district boundaries could radically alter the partisan and racial makeup of the U.S. House — without a single voter moving or switching parties. How we did this »

Go To:
Partisan goals
Other goals

Show current district boundaries

Gerrymander districts to favor Republicans

Gerrymander districts to favor Democrats

Match partisan breakdown of seats to electorate

Promote highly competitive elections

Maximize number of majority-minority districts

Make district shapes compact (using an algorithm)

Make districts compact while following county borders

← National map

Chance of being represented by either party

100% D
100% R
Usually Democratic districts Highly competitive districts Usually Republican districts
Current
Usually Democratic districtsHighly competitive districtsUsually Republican districts
Current

Party probabilities

Every district by the chance it will be represented by either party

Dem. chancesGOP chances
Democratic gerrymander
Compact (algorithmic)
Proportionally partisan
Highly competitive
Compact (borders)
Current
Majority minority
Republican gerrymander

Expected seat split

The expected number of seats controlled by Democrats and Republicans, based on their long-term likelihood of winning each district

Democratic gerrymander
Compact (algorithmic)
Proportionally partisan
Highly competitive
Compact (borders)
Current
Majority minority
Republican gerrymander

How the maps compare on district competitiveness, minority makeup, respect for local borders, compactness and the efficiency gap, an attempt to gauge how politically gerrymandered a set of districts is

Efficiency gap
A measure of “wasted” votes, by the size of the advantage and which party it favors
CompetitiveD+3%
ProportionalR+10%
Compact (borders)R+10%
Compact (algorithmic)R+10%
Dem. gerrymanderD+15%
GOP gerrymanderR+16%
Majority minorityR+16%
CurrentR+22%
Competitive districts
Number of districts in which both parties have at least a 1-in-6 chance of winning
Competitive6
Compact (algorithmic)3
Proportional2
Compact (borders)2
Current1
Majority minority1
Dem. gerrymander1
GOP gerrymander0
Majority-nonwhite districts
Number of districts in which a majority of the voting-age population is nonwhite
Majority minority1
Current0
Compact (algorithmic)0
Proportional0
GOP gerrymander0
Dem. gerrymander0
Competitive0
Compact (borders)0
County splits
Number of times a map divides counties into different congressional districts
Compact (borders)8
Majority minority10
Proportional11
Competitive14
GOP gerrymander15
Current15
Dem. gerrymander21
Compact (algorithmic)40
Compactness rank
Rank by the total length of district boundaries, from shortest to longest
Compact (borders)1
Competitive2
Majority minority3
Proportional4
Dem. gerrymander5
GOP gerrymander6
Compact (algorithmic)7
Current8

The racial or ethnic makeup of each district and each district’s likelihood of being represented by a member of a racial or ethnic minority, based on election results since 2006

White
African-American
Hispanic/Latino
Asian/Pacific Islander
Other
Minority coalition
Chance of being represented by a ...Chance of being represented by a ...
DistrictDistrictMajority Race
0%
50%
100%
Minority memberDemocratRepublican
1stWhite
2%16%84%
2ndWhite
3%>99%<1%
3rdWhite
1%50%50%
4thWhite
50%>99%<1%
5thWhite
<1%2%98%
6thWhite
<1%8%92%
7thWhite
<1%9%91%
8thWhite
1%10%90%

More from this series

METHODOLOGY

Methodology

We Drew 2,568 Congressional Districts By Hand. Here's How.

PODCAST & VIDEO

Podcast & Video

Gerrymandering 101

ESSAY

Essay

Hating Gerrymandering Is Easy. Why Is Fixing It So Hard?

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