How does redistricting work?
Every decade, states undertake the process of redrawing their district lines for federal and state representatives. The process varies by state, but there are certain requirements and factors that are considered when lines are drawn.
When are congressional district lines drawn?
During every year that ends in a zero, the Census Bureau conducts the decennial census to count the country’s population. After the census, reapportionment occurs to decide how many congressional seats each state receives, based on the most recent census count and compliance with one-person, one-vote. At the end of that year, the Census Bureau sends the data it has collected to states, which then usually conduct their redistricting process during the following year to draw district lines and determine which voters will vote in which district. The most recent census was conducted in 2020, and the next round of redistricting will start later this year. .
Who draws the lines?
The decision maker (or makers) responsible for drawing district lines varies from state to state.
- State legislatures: Legislatures draw congressional district lines in 31 states, and state legislature district lines in 30 states. These maps often follow the same legislative process as any other bill in the legislature, meaning they must pass the legislature and, in most states, can be vetoed or signed by the governor.
- Independent redistricting commissions: In other states, independent commissions, comprised of people who are not lawmakers or public officials, draw the lines.
- Political commissions: In some states, maps are drawn by a political appointee commission whose members are selected by lawmakers or party leadership. In Arkansas, maps are drawn by a commission made up of legislators themselves.
- Backup commissions: Some states have a backup commission that draws the lines if the legislature is deadlocked.
- Advisory commissions: In some states, an advisory commission drafts the maps, which are then voted on by the state legislature.
How are lines drawn?
Federal law mandates certain requirements for district lines.
- Equal population: Voting districts must contain equal populations, as mandated in the Equal Protection Clause of the 14th Amendment of the Constitution. Therefore, as people move around, states must update their district maps to ensure equal representation. Note that equal representation does not mean fair representation.
- Single-member congressional districts: Each congressional district will be represented by a single member.
- Voting Rights Act compliance: In order to combat state-sponsored racial intimidation and disenfranchisement, the Voting Rights Act of 1965 outlawed states’ attempts to deny or dilute minority communities’ right to vote. Section 2 prohibits any practices that interfere with minority voters’ ability “to participate in the political process and to elect representatives of their choice.” (However, given the June 2021 Supreme Court decision in Brnovich v. DNC that significantly undermined Section 2 of the Voting Rights Act, it is currently unclear how successful future challenges to gerrymandered maps will be.)
Beyond federal mandates, states often take into account several other factors when drawing district lines. These factors serve as a rulebook for mapdrawers, who can then be held accountable in court. The criteria vary in strength and effectiveness, so we have listed them below in order of effectiveness. Here a few examples of common criteria adopted by states:
- Contiguity: District should be a single, unbroken shape.
- Racial fairness: Maps should not intend to or have the effect of diluting the power of minority voters or their ability to elect candidates of their choice.
- Preserve communities of interest: Districts should keep communities together that share similar historical, cultural, policy, or economic interests or whose shared concerns would be affected by legislation. A community of interest should not be defined by political affiliation. A community of interest can include, for example, neighbors who have been advocating to increase public transit routes, residents who organized to prevent Amazon from moving into their city, or families with a shared interest to increase language access in public schools. Communities of interest can often share racial or ethnic backgrounds, but that cannot always be the sole identifier of that community.
- No advantages to political parties or candidates: Maps must not give partisan advantage to one party over another, or to specific candidates or incumbents.
- Political/geographic boundaries: Districts should try not to split existing city, town, or county boundaries.
- Compactness: Ideally, a district is relatively compact instead of sprawling across a state in order to include or exclude specific voters
However, politicians often employ several unethical strategies when attempting a partisan gerrymander.
- Cracking is the process of dividing up voters by party affiliation or race into separate districts in an attempt to reduce their political power.
- Packing is the process of jamming as many voters of a similar party or race into as few legislative districts as possible. That party will win in the “packed” districts, but nowhere else.
- Incumbent protection is when line drawers use any of the aforementioned methods to create districts that favor incumbent politicians over challengers.
A brief history of the word “gerrymander”
The word “gerrymander” originates from Massachusetts Governor Elbridge Gerry, who signed a redistricting map in 1812 in an attempt to ensure his party’s control of the state senate. A newspaper artist drew the head of a salamander onto the most egregious district and the practice of unfairly drawing district lines was dubbed “gerrymandering.”