Why do supporters of proportional representation describe elections as a census of opinion?

Supporters of proportional representation describe elections as a "census of opinion" because they believe the primary purpose of an electoral system is to create a legislative body that accurately reflects the full diversity of public opinion within a country.1

Advocates argue that this approach is essential for democratic legitimacy, as it ensures that the assembly’s decisions represent the actual distribution of support for various political parties. By contrast, they contend that plurality or majority systems often penalize weaker parties and can result in unrepresentative governments that hold power despite receiving only a minority of the popular vote. From this perspective, viewing an election as a census allows for a more precise mapping of the electorate's views, whereas critics argue that the function of an election should instead be to achieve a consensus for governance.1