An open primary is a primary election that does not require voters to be affiliated with a political party in order to vote for partisan candidates. In a traditional open primary, voters may select one party's ballot and vote for that party's nomination. As in a closed primary, the highest voted candidate in each party then proceeds to the general election. In a nonpartisan blanket primary, all candidates appear on the same ballot and the two highest voted candidates proceed to the runoff election, regardless of party affiliation. The constitutionality of this system was affirmed by the Supreme Court of the United States in 2008, whereas a partisan blanket primary was previously ruled to be unconstitutional in 2000. The arguments for open primaries are that voters can make independent choices, building consensus that the electoral process is not splintered or undermined by the presence of multiple political parties.
The open primary could be seen as good for voter participation. First, the open primary allows nonpartisan or independent voters to participate in the nominating process. If these voters are allowed to help select the nominees then they may be more likely to vote in the general election, since one of the candidates could be someone the non-partisan voter voted for. Also, a moderate member of one party may agree more with a candidate for the nomination of another party. This voter will have more of an incentive to participate in the general election if there is a nominee whom he or she agrees with.
The open primary could also be viewed as bad for voter participation. In Hawaii, primary voter turnout fell from 74.6% in 1978 to 42.2% in 2006 after changing to open primaries which could be the result of many things--not just the move towards the open primary system. The closed primary system had more of an incentive for people to join one of the major parties. This led to people being more involved in the voting process. With the open primary, some argue, more voters become independent and are less likely to participate in the nominating or election processes.
Opponents of the open primary believe that the open primary leaves the party nominations vulnerable to manipulation and dilution. First, one party could organize its voters to vote in the other party's primary and choose the candidate that they most agree with or that they think their party could most easily defeat. Secondly, in the open primary moderates and independent voters can vote in either party. This occurrence may dilute the vote of a particular party and lead to a nominee who does not represent the views of his or her particular party.
For example, in the 2008 presidential primaries, exit polls say John McCain failed to win a single race among Republican voters, up to Super Tuesday, yet during that same period he went from also-ran to front runner, because most non-Republicans who crossed over voted for him. In New Hampshire, Mitt Romney won among registered Republicans, but John McCain won overall . Likewise, in South Carolina, Mike Huckabee won among self-identified Republicans, but John McCain won the state .
Similarly, some Republican advocates called for Republicans to cross over and vote in the Democratic race, to help Barack Obama win, on the premise that Clinton had a better chance of beating their candidate. The Rush Limbaugh Show's "Operation Chaos" is the best known of these movements.
Opponents of the open primary argue that the open primary is unconstitutional. These opponents believe that the open primary law violates their freedom of association, because it forces them to allow outsiders to select their candidates. An opposing view is that political parties are not mentioned in the U.S. Constitution in any language, but voting rights of the individual are clearly defined.
Freedom of association has been recognized by the United States Supreme Court. First, in NAACP v. Alabama, the court said that "It is beyond debate that freedom to engage in association for the advancement of beliefs and ideas is an inseparable aspect of the "liberty" assured by the Due Process Clause of the Fifth and Fourteenth Amendment, which embraces freedom of speech."
In other words, the freedom of association is part of the freedom of speech. The freedom of speech, which is found in the First Amendment to the United States Constitution, is applied to the states through the fourteenth amendment. In Gitlow v. New York, Justice Sanford states that "[f]or present purposes we may and do assume that freedom of speech and of the press-which are protected by the First Amendment from abridgment by Congress-are among the fundamental personal rights and 'liberties' protected by the due process clause of the Fourteenth Amendment from impairment by the States."
This constitutionality raises a problem. The most popular alternative to the open primary is the closed primary. However, a mandatory closed primary can also be unconstitutional. In Tashjian v. Republican Party of Connecticut, the United States Supreme Court determined that Connecticut's closed primary law was unconstitutional. The Connecticut closed primary law "[required] voters in any political party primary to be registered members of that party." The Republican Party of Connecticut, however, wanted to allow independents to vote in the Republican primary if they so chose. The problem with this closed primary law was that it prevented the Republican Party from allowing independent "registered voters not affiliated with any party to vote in Republican primaries for federal and statewide offices." Since the Republican Party of Connecticut was not able to choose who it wanted to vote in the primary, the United States Supreme Court, in a 5-4 decision, stated that the closed primary law in Connecticut "impermissibly burdens the right of the Party and its members protected by the First and Fourteenth Amendments."
On October 1, 2007, the U.S. Court of Appeals for the Fourth Circuit ruled that the Virginia mandatory open primary statute was unconstitutional as applied to the Republicans because it imposed a burden on their freedom to associate under the First Amendment, although it explicitly did not rule on the question of whether an open primary law was in general unconstitutional as a burden on association.
California has adopted a new modified open primary that only applies to office holders other than Presidential delegate selections.
A third alternative is the "modified closed primary", as has been in effect in California since 2001. In California's primary since 2011 the voters are allowed as individual citizens to vote for any candidate, and the top two candidates regardless of party will advance to the general election. The Presidential election is exempt as it is a contest for delegates rather than a direct election for an office.
Prior to the California election reform of 2011, each political party could decide whether or not they wish to allow unaffiliated voters to vote in their party's primary. This appears to avoid the constitutional concerns of both the open and the closed primary. In the 2004 and 2006 primary elections, the Republican, Democratic, and American Independent parties all opted to allow unaffiliated voters to request their party's ballot. However, since the 2008 presidential primary election, only the Democratic and American Independent parties took this option, while the Republican party did not.
The state of Arizona has open primaries for all elections except for presidential primaries.
A similar system known as a nonpartisan blanket primary has been used in Louisiana for state and local elections since 1976, and began to be used in Washington, after numerous court challenges, in 2008.
In California, under Proposition 14, a measure that easily passed, traditional party primaries were replaced in 2011 with wide-open elections. Proposition 14, known as the open primary measure, gave every voter the same ballot in primary elections for most state and federal races, except the presidential contest.
Most primaries in New York are closed, but state law contains a provision allowing parties to use a different method if they want. Currently, only the Independence Party chooses to allow unaffiliated voters to participate.