An open primary is a primary election in which voters may cast votes on a ballot of any party. This distinguishes it from a closed primary, another type of primary election in which voters are limited by party affiliation. A related concept, the blanket primary, allows voters to vote for candidates of any party. The United States is one of the only nations in the world which uses a primary system, and the issues and advantages of the open primary are often a subject of debate in American politics, especially during election season.
In a primary election, voters indicate their preference for a candidate of a particular party to advance to the race for an office. For example, a voter might indicate his or her support for Green Party candidate X over all the other potential Green Party candidates. If that candidate wins enough votes at the primary, he or she will compete against candidates from other parties. The primary system is most commonly used for Presidential elections, because it allows each political party to get an idea of what kind of support a candidate has nationwide.
The idea of holding primaries before general elections arose in the early twentieth century, when the Progressive movement in America was trying to empower the populace. Advocates of the system proposed that using primaries would put more power into the hands of the people, instead of concentrating it with the political parties. An open primary reflects these ideals, since it allows voters more input on the process of nominating a candidate.
In classic closed primary, a Democratic voter receives a Democratic ballot, a Republican voter receives a Republican ballot, and so forth. In an open primary, a voter may request a ballot from any political party, regardless as to his or her personal party affiliation. In a blanket primary, a voter receives a general “blanket” ballot which allows him or her to vote for any candidate from any party. This would allow a voter to support a Libertarian candidate for President while simultaneously voicing preference for a Peace and Freedom Gubernatorial candidate, for example. The blanket primary is a natural extension of the open primary system, but very few states use it.
There are some distinct disadvantages to an open primary. It is not uncommon for voters from one party to request the ballot of an opposing party and vote for the weakest candidate, in the hopes of nominating that weaker candidate to the race for office. An open primary also allows voters to easily defect from their stated party affiliation. However, independents and people who have no party affiliation appreciate the open primary, as it allows them to participate in the democratic process without allying themselves to a particular political party.