How can a party win more legislative seats than an opponent despite receiving fewer votes under a plurality system?

Under a plurality system, it is possible for a party to win more legislative seats than an opponent despite receiving fewer total votes because the system relies on single-member districts rather than a national proportional count.12

This outcome occurs because plurality systems reward the strongest party in each individual district, regardless of the margin of victory. A party can win a majority of seats by:

• Winning narrow victories in many districts: A party may win many seats by small margins, while its opponent wins fewer seats by very large margins (effectively "wasting" their surplus votes in those specific districts).1
• Geographic concentration: If a party’s support is efficiently distributed across many districts, it can secure a legislative majority even with a minority of the total national vote.1
• Gerrymandering: Political actors may manipulate district boundaries to concentrate an opponent's voters into a few districts or spread them thinly across many, ensuring their own party wins a higher number of seats than their popular vote share would otherwise suggest.34

Because these systems do not aim for a direct correspondence between popular vote and seat share, they often produce results that favor larger parties and penalize smaller ones.52