Every ten years, a new set of district maps comes out. Within days, someone online is calling one of them “a textbook gerrymander.” The shapes look strange. The strangeness is the entire point.

What does “gerrymandering” mean?

Gerrymandering is drawing electoral district boundaries to benefit one political group. It’s not about reflecting population and community lines fairly. The map becomes a tool for shaping outcomes before a single vote gets cast.

Where did the term come from?

The word dates to 1812. That year, Massachusetts governor Elbridge Gerry signed off on an oddly shaped state senate district. A newspaper cartoonist drew it with wings, claws, and a head, and the result looked like a salamander. “Gerry-mander” stuck as a label for the practice, even though Gerry wasn’t the one who actually drew the map himself.

How does a district actually qualify as gerrymandered?

Two techniques do most of the work. “Packing” concentrates voters of one type into as few districts as possible. Their votes pile up in lopsided wins that don’t matter beyond that single seat. “Cracking” does the opposite. It spreads those same voters thinly across many districts, so they never reach a majority anywhere. Either way, the map does work an election is supposed to do on its own.

For a district to count as gerrymandered, not just unusually shaped, there needs to be a clear beneficiary. That’s a group whose voting power increases specifically because of how the lines were drawn. And that increase has to depart from neutral criteria, like compactness or keeping existing communities intact. Even when a map avoids extreme, cartoonish shapes, subtler versions of the same effect can hide inside districts that look reasonable at a glance. That’s part of why courts increasingly rely on statistical measures of vote-to-seat gaps, rather than a map’s visual appearance alone.

Gerrymandering isn’t limited to one party benefiting at another’s expense, either. It can also protect incumbents of both parties at once. Carving safe seats for everyone already in office trades competitive elections for mutual job security. This version draws less attention than the partisan kind. But it may be just as consequential, since it quietly reduces how many districts are ever genuinely competitive in the first place. Modern mapping software using precinct-level voting data has also made the whole practice far more precise than it was in Gerry’s era. Map-drawers can now predict outcomes down to individual streets, rather than broad regions.

The effects can be dramatic. A party can lose the statewide popular vote and still hold a comfortable majority of legislative seats, purely because of how the lines were drawn. Researchers treat that gap between vote share and seat share as one of the clearer signals something is off with a given map. That gap has also factored into several redistricting court challenges. It offers a measurable way to talk about an outcome that would otherwise just look like an argument over shapes on a map.

A concrete example

A district might snake for miles along a highway corridor. It links distant, demographically similar neighborhoods while carving carefully around the ones next door. The resulting shape has no compact form and no obvious geographic logic — except for the voting math that built it.

What it’s not

Gerrymandering isn’t the same as redistricting itself. Every state has to redraw districts after each census, regardless of intent, simply to keep populations roughly equal. Redistricting is the neutral, required process. Gerrymandering is what happens when that process steers toward a specific partisan outcome instead of a fair one.

Where you’ll encounter it

The term resurfaces heavily after every census and in court challenges to specific maps. It also shows up in ongoing coverage of which states use independent commissions versus legislature-drawn maps to decide district lines.

Related terms

• Proxy War (L01)
• Dog Whistle (L02)