Politics & Government
How Partisan Gerrymandering Fuels Political Polarization
Quick fact
In the 2012 U.S. House elections, Democrats won more than one million more votes nationwide than Republicans, yet Republicans kept a comfortable majority in the House—a result shaped significantly by how districts were drawn. This gap between votes and seats is a direct product of partisan gerrymandering, and it deepens polarization by making safe seats the norm.
Why this is interesting
You've heard that gerrymandering is unfair, but did you know it might be literally pushing politicians to the extremes? Why would drawing lines on a map make a congressman more radical?
Read the full explanation
Understanding How Partisan Gerrymandering Fuels Political Polarization
Imagine a state with 10 districts. The party in power gets to draw the district lines. They can use two tricks: 'cracking' (spreading the opposing party's voters across many districts so they are a minority in each) and 'packing' (concentrating the opposing party's voters into a few districts so they waste their votes in landslide wins). The result is that even a party with a minority of overall votes can win a majority of seats. More importantly, most districts become 'safe' for one party, meaning the general election is essentially decided in the primary. In a primary, turnout is low and voters tend to be more ideologically extreme. To win the primary, candidates must appeal to these extremes rather than the broad middle. Hence, gerrymandering indirectly pushes both parties' representatives away from the center, fueling polarization.
A deeper explanation
The core mechanism is the change in electoral incentives. In a competitive district, a candidate needs to appeal to the median voter—who is typically moderate—to win the general election. But in a safe district, the real battle is the primary, where only the most partisan voters show up. To survive the primary, candidates must take increasingly extreme positions. This is a structural incentive, not just a matter of personal ideology. The effect is amplified over time: as incumbents move to the edges, party bases become more polarized, which increases the likelihood of primary challenges from even more extreme contenders, creating a feedback loop. Additionally, gerrymandering reduces electoral accountability because the only risk to an incumbent is from within their own party, not from the general electorate. This makes it harder for the average voter to moderate policy outcomes, as the most extreme voices are the ones that matter.