History
The Impact of Gerrymandering on Electoral Competitiveness
Quick fact
In some states, gerrymandered districts are so safe that fewer than 10% of races are considered competitive, meaning most voters know the winner long before election day.
Why this is interesting
In the 2012 U.S. House elections, Democrats won more than a million more votes nationwide than Republicans—yet Republicans kept a comfortable majority of seats. How can a party lose the popular vote and still win big?
Read the full explanation
Understanding The Impact of Gerrymandering on Electoral Competitiveness
Imagine drawing a map of a neighborhood where you get to decide the borders. If you’re clever, you can put all your opponents' homes in one small area (packing) or split them up so they’re a minority in many areas (cracking). That’s gerrymandering. In the U.S., state legislatures draw congressional districts every ten years after the census. By manipulating those boundaries, a party can turn a statewide 50-50 split of voters into a 60-40 advantage in seats. This makes elections less competitive because most districts become 'safe' for one party. When a district is safe, the real contest happens in the primary, and the general election is a foregone conclusion. As a result, politicians don’t have to worry about appealing to the other side, and voters feel their vote doesn’t matter.
A deeper explanation
Gerrymandering works because of winner-take-all, single-member districts. In each district, the candidate with the most votes wins, and the loser gets nothing. If you can draw the lines, you can decide which voters end up in which district, effectively wasting the other party's votes. The two main techniques are cracking and packing. Cracking spreads opposing voters across many districts so they can't form a majority anywhere. Packing concentrates them into one district, giving that party a landslide win while wasting their surplus votes. Both reduce competitiveness: packed districts produce lopsided wins, and cracked districts are so spread out that the minority is always outvoted. The impact is profound: gerrymandered maps lead to fewer competitive races, greater partisan polarization, and less responsiveness to public opinion. Because safe seats are nearly guaranteed, incumbents face challenges only from their own party's extremes, pushing policy toward the edges. This undermines the principle that elections should be a contest of ideas, and it erodes public trust. Reforms like independent redistricting commissions or algorithmic map-drawing can help, but the core mechanism remains a central challenge to electoral fairness.