Free and fair elections are the foundation of democratic societies. But not all elections are the same. There are two main types of election systems: single member, simple plurality, or SMSP, and proportional representation. 

This article will explain how they both work and how they correspond to elections in the United States and around the world. 

Single member, simple plurality 

The SMSP system is used in the United States along with 62 other countries around the world for their legislatures. To win an election, a candidate needs to receive the most votes in their district. Local rules dictate whether the total must be an outright majority (more than 50 percent) or a plurality of votes cast. 

Pros of the SMSP system:

• Greater accountability of representatives to the voters because one person represents one district
• Encourages aggregative, coalition politics at the electoral level, before the election, as parties that don’t have a chance of winning a plurality have incentives to combine with larger parties that are closer to their preferred policy preferences

Presidential elections 

The U.S. president is elected using the Electoral College, which is separate from the SMSP elections used in most other races in the United States. Each state has its own election and the plurality of the vote decides who gets the electors from that state. In this case we have a multi-member, simple plurality, rather than a single member, simple plurality. 

A candidate needs 270 electoral votes to win the presidency out of the possible 538. A state’s electoral votes are equal to the number of representatives in the U.S. Congress plus its two U.S. senators. Wyoming has one House seat plus two Senators, so three electoral votes. After the 2020 census, California has two senators and 52 House seats totaling 54 electoral votes. 

Proportional representation 

Proportional representation systems allow voters to cast ballots for a party which is then awarded seats in a legislative body based on their percentage of the total vote. In other words, there’s a proportional representation of seats based on votes. 

Here’s an example: If a city council has 10 open seats, multiple political parties can have 10 of their members run in the same election. If party one receives 50 percent of the vote, it gets five representatives on the council. If party two receives 20 percent of the vote, it earns two seats. If party three receives 30 percent, it earns three seats.

96 countries, including 40 in Europe, use this system.

Pros of proportional representation:  

• Increases fairness because there is a closer relationship between seats to votes
• Encourages minor parties because they can win representation with a smaller share of the vote
• Encourages coalitions between parties post-election 
• Avoids gerrymandering

To learn more about voting and elections in America, including voter registration and convenience voting, visit our voter integrity page.