Margin of victory in state legislative elections before and after 2010 census redistricting

## Contents

* 1 What is redistricting?
* 2 Methodology
* 2.1 Chamber selection
* 2.2 Margin of victory
* 3 Methods of redistricting
* 3.1 Legislature
* 3.2 Appointed commission
* 3.3 State executives
* 3.4 Computer-generated
* 4 Impact of redistricting
* 5 Context
* 5.1 Massachusetts
* 5.2 Florida
* 6 See also
* 7 Footnotes

In a study of competitive districts in both 2010 and 2012, Ballotpedia found that across 44 state legislative chambers there were 61 fewer competitive general elections overall in 2012 than in 2010. The largest change occurred in two states: Florida and Massachusetts. Florida's legislature had 18 more seats with competitive or mildly competitive general elections in 2012. Massachusetts, on the other hand, had 18 fewer competitive or mildly competitive legislative general elections in 2012.

Twenty-five chambers had a net loss of competitive general elections, while 17 saw a net increase. One chamber, the Minnesota House of Representatives, saw no change in the number of competitive general elections. In total, 623 (16.2%) of 3,842 races had competitive general elections in 2010, while only 561 (14.6%) of those races had competitive general elections in 2012. This means that there was a net decrease of ten percent in competitive general elections between the two years.

In just the 25 chambers with a net loss, there were 2,231 seats up for election in both years. In 2010, there were 288 (12.9%) competitive general elections, while in 2012 that number fell to 162 (7.3%) for a decrease of 43.8 percent. The 17 chambers with a net increase saw a 39.5 percent change from 2010 to 2012, with 162 (10.1%) competitive general elections of a possible 1,611 in 2010 compared to 226 (14.0%) in 2012.

## What is redistricting?[edit]

See also: Redistricting

Redistricting is the process of re-drawing Congressional and state legislative districts using updated census figures. Every 10 years, following the census, each of the 50 states takes up the process of creating new maps to accurately reflect the updated population levels. This practice has been in place since the 1960s, when the Supreme Court ruled that all districts must be roughly equal in population.[1]

## Methodology[edit]

### Chamber selection[edit]

To be selected for this study, a state legislative chamber needed to meet the following criteria:

* Hold elections in both 2010 and 2012
* Completed redistricting between the 2010 and 2012 elections
* Have the same seats up for election in 2010 as 2012

### Margin of victory[edit]

The top vote-getter in a district was compared to the next highest. In cases of multi-member districts, the winner with the lowest vote total was compared to the next lowest. The difference between the two numbers was divided by the total number of votes to get the margin of victory percentage.

Districts where the margin of victory was 5 percent or less were considered "competitive." A margin of victory ranging from 5 to 10 percent qualified a district as "mildly competitive."

## Methods of redistricting[edit]

### Legislature[edit]

By far the most popular method, legislative redistricting is the method used by 23 of the 36 states used in this study. Legislative redistricting typically involves a redistricting committee, which creates the maps that are introduced on the floor of the full chamber. Governors typically hold veto power over these redistricting bills as they do any other.

### Appointed commission[edit]

The other primary method of redistricting involves a commission of individuals appointed by politicians to lead the process. This method is used in 11 of the remaining 13 states in this study. Commissions can either be split in terms of partisan balance or dominated by one party. In Arizona, for example, one member is chosen by the Senate President, Senate Minority Leader, House Speaker and House Minority Leader before those four members choose a fifth Independent member, so there is an even partisan split. In Ohio, on the other hand, where the commission is made up of the Governor, State Auditor, Secretary of State and a member chosen by each of the major political parties, four of the five members were Republican.

### State executives[edit]

In Arkansas, three specific individuals make up their Arkansas Board of Apportionment: the Governor, Secretary of State and Attorney General. There are no appointed members on this board and partisan affiliations do not affect membership. For this cycle of redistricting, the board contained two Democratic members and one Republican member.

### Computer-generated[edit]

Iowa uses a computer program to generate maps only with respect to population. The Legislature must still approve the final maps, but the process has not been highly contentious in the past. State law helps dictate how the maps are generated. County- and city-splitting rules are taken into account, as is the rule that district populations must not deviate from greater than 1 percent of the ideal.

## Impact of redistricting[edit]

The following table compares the number of competitive or mildly competitive elections held in a chamber from 2010 to 2012.

Overall, 61 fewer elections were competitive in 2012 than in 2010 across 44 chambers, for an average of 1.4 seats per chamber.

* Legislative redistricting resulted in 40 fewer competitive elections across 27 chambers, for an average of 1.5 seats per chamber.
* Appointed commissions resulted in 27 fewer competitive elections across 15 chambers, for an average of 1.8 seats per chamber.
* The Arkansas House of Representatives, the only chamber to have its redistricting decided by state executives, had 8 more competitive elections.
* The computer-generated redistricting in the Iowa House of Representatives resulted in 2 fewer competitive elections.

Legend: Increase in competitive races Decrease in competitive races

States compared by incumbents with primary opposition

Chamber  |  2012 Competitive Races  |  2012 Mildly Competitive Races  |  2010 Competitive Races  |  2010 Mildly Competitive Races  |  Difference in Competitive Races  |  Difference in Mildly Competitive Races  |  Total Difference  |  Method
Arizona Senate |  1  |  3  |  0  |  2  |  1  |  1  |  2  |  Appointed commission
Arizona House |  10  |  2  |  7  |  6  |  3  |  -4  |  -1  |  Appointed commission
Arkansas House |  7  |  10  |  6  |  3  |  1  |  7  |  8  |  State executives
California Assembly |  4  |  5  |  2  |  5  |  2  |  0  |  2  |  Appointed commission
Colorado House |  3  |  7  |  8  |  6  |  -5  |  1  |  -4  |  Appointed commission
Connecticut Senate |  7  |  2  |  5  |  3  |  2  |  -1  |  1  |  Legislature
Connecticut House |  9  |  12  |  20  |  13  |  -11  |  -1  |  -12  |  Legislature
Delaware House |  3  |  4  |  3  |  5  |  0  |  -1  |  -1  |  Legislature
Florida House |  14  |  10  |  4  |  2  |  10  |  8  |  18  |  Legislature
Georgia Senate |  0  |  1  |  0  |  0  |  0  |  1  |  1  |  Legislature
Georgia House |  4  |  4  |  1  |  5  |  3  |  -1  |  2  |  Legislature
Hawaii House |  3  |  0  |  4  |  2  |  -1  |  -2  |  -3  |  Appointed commission
Idaho Senate |  2  |  2  |  2  |  3  |  0  |  -1  |  -1  |  Appointed commission
Idaho House |  4  |  6  |  3  |  5  |  1  |  1  |  2  |  Appointed commission
Illinois House |  4  |  2  |  4  |  6  |  0  |  -4  |  -4  |  Legislature
Indiana House |  9  |  12  |  12  |  10  |  -3  |  2  |  -1  |  Legislature
Iowa House |  18  |  9  |  16  |  13  |  2  |  -4  |  -2  |  Computer-generated
Kansas House |  9  |  15  |  10  |  10  |  -1  |  5  |  4  |  Legislature
Massachusetts House |  7  |  3  |  15  |  13  |  -8  |  -10  |  -18  |  Legislature
Michigan House |  8  |  13  |  8  |  12  |  0  |  1  |  1  |  Legislature
Minnesota House |  17  |  21  |  24  |  14  |  -7  |  7  |  0  |  Legislature
Missouri House |  15  |  5  |  9  |  5  |  6  |  0  |  6  |  Appointed commission
Nevada Assembly |  5  |  4  |  3  |  2  |  2  |  2  |  4  |  Legislature
New Hampshire Senate |  5  |  3  |  2  |  7  |  3  |  -4  |  -1  |  Legislature
New Mexico House |  9  |  6  |  5  |  5  |  4  |  1  |  5  |  Legislature
New York Senate |  8  |  1  |  6  |  4  |  2  |  -3  |  -1  |  Legislature
New York Assembly |  4  |  6  |  7  |  9  |  -3  |  -3  |  -6  |  Legislature
North Carolina Senate |  2  |  4  |  5  |  6  |  -3  |  1  |  -2  |  Legislature
North Carolina House |  9  |  6  |  10  |  11  |  -1  |  -5  |  -6  |  Legislature
Ohio House |  7  |  10  |  14  |  9  |  -7  |  1  |  -6  |  Appointed commission
Oklahoma House |  3  |  4  |  8  |  4  |  -5  |  0  |  -5  |  Legislature
Oregon House |  4  |  5  |  3  |  9  |  1  |  -4  |  -3  |  Legislature
Rhode Island Senate |  1  |  1  |  5  |  4  |  -4  |  -3  |  -7  |  Appointed commission
Rhode Island House |  3  |  7  |  10  |  7  |  -7  |  0  |  -7  |  Appointed commission
South Carolina House |  2  |  0  |  2  |  4  |  0  |  -4  |  -4  |  Legislature
South Dakota Senate |  3  |  5  |  1  |  5  |  2  |  0  |  2  |  Appointed commission
South Dakota House |  12  |  5  |  13  |  7  |  -1  |  -2  |  -3  |  Appointed commission
Tennessee House |  6  |  3  |  6  |  7  |  0  |  -4  |  -4  |  Legislature
Texas House |  4  |  5  |  12  |  7  |  -8  |  -2  |  -10  |  Legislature
Vermont Senate |  2  |  4  |  7  |  2  |  -5  |  2  |  -3  |  Appointed commission
Washington House |  7  |  9  |  11  |  11  |  -4  |  -2  |  -6  |  Appointed commission
West Virginia House |  18  |  9  |  13  |  10  |  5  |  -1  |  4  |  Legislature
Wisconsin Assembly |  11  |  4  |  14  |  6  |  -3  |  -2  |  -5  |  Legislature
Wyoming House  |  5  |  1  |  3  |  2  |  2  |  -1  |  1  |  Legislature

## Context[edit]

### Massachusetts[edit]

See also: Redistricting in Massachusetts

Original political cartoon portraying a district created by Gov. Thomas Gerry for political gain.

The Massachusetts House of Representatives shared the single-largest change in competitive elections from 2010 to 2012, with 18 fewer competitive races. This chamber also has the single largest partisan seat count disparity with Democrats holding 102 more seats than Republicans. The new legislative maps doubled the amount of minority-majority districts in the chamber from 10 to 20.[2]

The most recent round of redistricting in the state drew criticism and calls for an independent commission, with 66% of polled citizens in favor of such a commission.[3] In 2009, the Massachusetts House of Representatives rejected a plan for an 8-member independent commission to take on the task of redistricting.[4]

Massachusetts has a history of messy redistricting. Last time redistricting occurred, the presiding House Speaker -- Thomas Finneran -- ended up pleading guilty to obstruction of justice in a federal court.[5] The term of "gerrymandering," which describes redistricting when used as a tool for political advantage, was coined in reaction to Massachusetts Governor Thomas Gerry's oddly-shaped districts, created for political gain.[6]

### Florida[edit]

See also: Redistricting in Florida

Florida's state house districts prior to 2010 redistricting

Contrary to Massachusetts, the Florida House of Representatives had 18 more competitive races in 2012 than in 2010. Republicans control the chamber, holding 30 more seats than their Democratic colleagues. The latest round of redistricting was mired in criticism and legal challenges.

Florida previously featured oddly-drawn districts such as District 78. The Tampa Bay Times featured the district in an article, noting that it had not held a general election for the seat since redistricting in 2000 because of the number of Democrats packed into the district. Then-Rep. Steven Perman (D) said the district was "incredibly oddly drawn [and] I'm expecting the district will look like something different in 2012. And I'm OK with that."[7]

Approved by voters in 2010, the "Fair Districts" Amendment played a role in this round of redistricting. The amendment required districts not to be drawn in favor of an incumbent or political party, not marginalize racial or language minorities, be contiguous and use existing city, county and geographical boundaries when feasible.

## See also[edit]

* Redistricting
* State legislative elections, 2012
* State legislative elections, 2010

## Footnotes[edit]

1. ↑ All About Redistricting, "What is redistricting?" accessed December 9, 2014
2. ↑ Mass Live, "Massachusetts legislators release maps of proposed new seats for state Senate, House," October 18, 2011
3. ↑ Patriot Ledger, "Poll: Public favors independent panel for congressional redistricting," January 12, 2011
4. ↑ Bedford Minuteman, "House okays redistricting, reorganization plans," March 6, 2009"
5. ↑ Boston Herald, "Massachusetts pols brace for redistricting battles," December 4, 2010
6. ↑ University of California - San Diego, "The politics of Gerrymandering," accessed August 20, 2014
7. ↑ Tampa Bay Times, "House District 78: A lesson on redistricting," April 5, 2011

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