Proportional representation (PR) refers to any type of electoral system under which subgroups of an electorate are reflected proportionately in the elected body. The concept applies mainly to political divisions (political parties) among voters.

Proportional Representation. An election system in which each party running receives the proportion of legislative seats corresponding to its proportion of the vote.

In 48 states and Washington, D.C., the winner gets all the electoral votes for that state. Maine and Nebraska assign their electors using a proportional system. A candidate needs the vote of at least 270 electors—more than half of all electors—to win the presidential election.

The founders thought that the use of electors would give our country a representative president, while avoiding a corruptible national election. The Records of the Federal Convention of 1787 report that, ... [T]he members of the General Convention...