A blanket primary is a type of voting system used in the United States to establish candidates for a general election held at a later time. Voters are able to choose from a list of candidates for office. Those candidates with the most support are then placed on the ballot in the general election which will then determine who goes on to hold the office for the term. The purpose is to narrow the field of choices for voters with the goal of establishing stronger candidates. It is designed to prevent a large number of candidates vying for the same post, which may result in no clear majority winner.
The blanket primary system allows the individual voter to switch between political parties when deciding candidates for a particular office. Open primaries are party-specific, calling for voters to pick only Republican, Democratic or other party officials. Blanket primaries on the other hand, permit the electorate to choose from the Democratic candidates for one office, while picking from Republicans for another.
The main advantage to the blanket primary system is that it allows voters to make decisions for particular offices without having to vote along party lines. Most political analysts believe this helps keep the parties more moderate because a majority of voters could decide to choose centrist politicians down the line rather than allow the party extremists to act as the main voice for the electorate. Drawbacks to the system, as strongly voiced by the major parties themselves, include a lack of loyalty to the party's candidates. A situation can also arise when members of another party use tactical voting to oust potential candidates from the general election. For example, large numbers of Republicans can vote against the strongest Democratic candidate to ensure he or she does not end up on the final ballot.
Blanket primaries were used in four states until the year 2000: Alaska, California, Louisiana and Washington. That year, the Supreme Court struck down the laws supporting a blanket primary, forcing the states to switch to an open primary election system. The concept survives under a different form in Louisiana, which allows for nonpartisan voting in the primaries. Candidates can still be chosen regardless of political affiliation, but do not run with the support of any particular party.