Gerrymandering meaning: how lines on a map can shape results

Gerrymandering definition: who draws the lines

To define gerrymandering, start with how districts work. Many countries split voters into districts (also called constituencies or seats), and each district elects one representative. Someone has to decide where the boundaries go. The definition of gerrymandering covers cases where those boundaries are drawn not to keep communities together or to make districts equal, but to help or hurt a particular side.

The word can describe different aims:

• Partisan gerrymandering: favouring one political party.
• Racial gerrymandering: diluting or concentrating the votes of a racial or ethnic group.
• Incumbent protection: drawing safe seats so that sitting members are hard to defeat, sometimes agreed across parties.

Packing and cracking: a worked example

Imagine a small state with 50 voters and five districts of 10 voters each. Thirty voters support the Blue party and twenty support the Orange party.

In map C the smaller party wins the most seats. Two tricks make that possible:

• Packing: squeezing the rival side's voters into a few districts, where they win by huge, "wasted" margins.
• Cracking: splitting the rival side's remaining voters across many districts so they fall just short everywhere.

How the word was born

The term first appeared in the Boston Gazette on 26 March 1812, written with a hyphen between its two halves. That year the Massachusetts legislature redrew its state senate districts, and the state governor, whose surname forms the first half of the word, signed the plan. One district north of Boston had such a twisting outline that a cartoon showed it as a winged, dragon-like salamander. Critics joined his surname to the creature, and the word stuck.

The governor's surname is said to have been pronounced with a hard g, as in get, but the soft j sound became standard for the word long ago.

Gerrymandering meaning in US law and elsewhere

• United States: in many states the state legislature draws congressional and state districts, while some states hand the job to independent or bipartisan commissions. The US Supreme Court has ruled that federal courts cannot decide claims of partisan gerrymandering, though state courts may hear them under state constitutions. Maps drawn mainly by race can be challenged under the Constitution and the Voting Rights Act.
• India: constituency boundaries are set by a Delimitation Commission, a body created by law for that task, rather than by the parties in power. People still debate its decisions at times, but the system is designed to keep the job at arm's length from politicians.
• United Kingdom and many other countries: independent boundary commissions review seats on a regular cycle.

Why people argue about it

Critics say gerrymandering lets politicians choose their voters instead of voters choosing their politicians, creates safe seats where general elections matter little, and can weaken minority communities. Defenders of legislature-drawn maps reply that any map has political effects, that keeping communities or local boundaries together sometimes produces odd shapes, and that elected bodies are accountable to voters in a way commissions are not. There is also debate over which measures of fairness to use, such as compactness, equal population, or how closely seats match the overall vote share. Both sides of this debate draw on the wider ideas found on our democracy and federalism pages.

Using the word

• The court ordered the state to redraw the gerrymandered map before the next election.
• Reformers want an independent panel to stop gerrymandering in their state.
• Opponents accused the council of gerrymandering school zones to keep certain families out.
• The district snakes along a highway for sixty miles, a shape critics call a textbook gerrymander.

Notice that the word now stretches beyond elections, to any boundary drawn for advantage, such as school catchment areas or sales territories. For more civic vocabulary, see our law and society words.