Proportional Representation in Presidential Elections
The Democratic Party uses proportional representation in its primaries and caucuses to nominate presidential candidates. Any candidate who wins at least 15% of the vote in a primary or at a caucus is entitled to a fair share of delegates based on their share of the vote in that state. In a primary, the vote is based on statewide totals. For caucuses like those in Iowa, the threshold applies in each caucus, and participants may choose to support a second choice candidate if their first choice is unlikely to have enough support to elect a delegate.

The Republican Party allocates delegates by full representation in some states like Iowa and New Hampshire, but in many states uses systems based on winner-take-all (whichever candidate finishes first taking all delegates) or winner-take-all by district. 

In general elections, all states except Maine and Nebraska now allocate electors by winner-take-all based on the statewide vote: Maine and Nebraska allocate two electors to the statewide winner and one elector to the first-place finisher in each U.S. House district. In the past, some states allocated electoral votes by proportional representation.

[More on presidential primaries]
Recent Articles
October 19th 2009
A better election system
Lowell Sun

Election expert Doug Amy explains how choice voting can "inject new blood" into the elections of Lowell (MA), and give voters a greater incentive to participate.

October 16th 2009
Haven't Detroit voters spoken enough?
Livingston Daily

In Detroit, there have been three mayors in the past two years and the current one has come under scrutiny. Perhaps a system like instant runoff voting will help bring political stability to motor city.

August 21st 2009
Black candidate for Euclid school board to test new voting system
Cleveland Plain Dealer

Limited voting, a form of proportional voting, will be used in Euclid (OH), in the hopes of allowing better representation of minorities.

July 2nd 2009
Reforming Albany
New York Times

FairVote's Rob Richie responds in a letter to the editor making the case for proportional voting systems to bring substantive reform to New York's legislature.