Report Primaries: More than One Way to Find a Party Nominee

A century ago, political parties did not select their nominees through primary elections. Instead, parties ran their own processes using their own rules, and hearing from—mostly—party stalwarts, with little role for rank-and-file members. In other words, nominees were selected in the proverbial smoke-filled back room.

Half a century ago, primaries were still uncommon. By then, in an effort to be more inclusive, caucuses had largely replaced insider decision-making. At a caucus, the rank-and-file could express support for the candidates of their choice. Still, only highly motivated party members attended caucuses, then or now.

Over the last few decades, most parties have switched from caucuses to primary elections to select their nominees for general elections. The motivating factor was—again—to permit participation by more party members, continuing a century-long trend.

Of course, state practices regarding primaries vary considerably. Perhaps the most important variable is, who can participate in the primary? It used to be that only members of a party—those who had affirmatively registered with that party—could participate. That is still the case in eight states, and there is a strong rationale: A primary is a party function, so shouldn’t party members be the only ones to choose their nominees? Courts have been largely supportive of this reasoning.

After the theoretical debate about whether a party primary should allow nonparty members to participate, turnout is often the next concern. Many elements impact turnout besides the type of primary used: whether statewide candidates are on the ballot (especially if it is a hotly contested race), traditional patterns of voter participation in the state, the level of partisanship in the state (the more partisan, the higher participation in primaries) and even the weather.

That said, primary type matters too. The Bipartisan Policy Center’s (BPC) report, 2018 Primary Election Turnout and Reforms, notes that 19.9% of the eligible electorate participated in 2018’s state primaries. To increase turnout in primaries, it referenced an earlier BPC report, Governing in a Polarized America: A Bipartisan Blueprint to Strengthen our Democracy, recommending that states “adopt open or semi-open primaries to allow independents and/or members of the opposite party to cast ballots in a political primary.” Most research points to a small but measurable increase in turnout correlating with how open a primary is. See:

Overview

This report answers many of the key questions legislators may have if they are considering changing their state’s primary type. This report does not attempt to answer questions about presidential preference primaries.

Section 1 looks at who can participate in a primary, and the merits of different options.

Section 2 looks at the legal landscape on primaries, summarizing guidance from the Supreme Court.

Section 3 answers these questions: 

Section 4 reviews the nexus between ranked choice voting and primary elections.

Section 5 and Section 6 provide tables, resources and acknowledgements.

For more information, please contact NCSL’s elections and redistricting team.

Section 1: Primary Systems in Use in the United States

In most states, political parties use primaries to select their nominees to run in the general election. How those primaries work varies state by state. The common ground is that, throughout the nation, only registered voters can participate in primaries.

But can every registered voter participate in a primary? That question is more alive now than ever. On one hand, it seems to make sense that allowing all voters, not just those affiliated with a party, would increase turnout in primaries.

On the other hand, the constitution gives Americans the right to free association, and a state telling a party that they must include others may tread on that right. Telling a party that they can’t include others may tread on that right as well. Litigation is not decisive on this point; see Section 2 for more details on the legal landscape for primaries.

Political analysts use the phrases “open” and “closed” to refer to various primary systems, but those categories are too broad for detailed comparisons. NCSL has created a taxonomy that is more precise. It is based entirely on who gets to vote in the primary: just registered members of the party, or other voters too—and if so, which other voters?

These definitions are detailed below, ordered from most restrictive to most open. See Table 1 for a summary table of primary types.

Closed Primaries

A voter seeking to vote in a closed primary must first be a party member. Typically, the voter affiliates with a party on his or her voter registration application, and it is through an update to the voter registration record that party affiliation changes can be made. This system deters “cross-over” voting by members of other parties, or by independent or unaffiliated voters, and may contribute to a strong party organization.

Unaffiliated voters: Cannot participate.

Ten states use closed primaries: Delaware, Florida, Kentucky, Maryland, Nevada, New Hampshire, New Mexico, New York, Oregon and Pennsylvania.

Partially Closed Primaries

In this system, state law permits political parties to choose whether to allow voters unaffiliated with any party to participate in their nominating contests. The decision can shift before each election cycle. In this system, parties can still exclude members of opposing parties. This system gives the parties more flexibility from year-to-year about which voters to include, and it gives the two parties power over their own systems—they do not have to make the same choice. At the same time, it can create uncertainty about whether or not certain voters can participate in party primaries in a given year. 

Unaffiliated voters: May be able to participate, depending on the party’s decision.

Seven states use partially closed primaries: Alaska, Connecticut, Idaho, North Carolina, Oklahoma, South Dakota and Utah.

Open to Unaffiliated Voters

A number of states require that parties allow unaffiliated voters to participate in the primary of their choice (while prohibiting voters who are registered with one party to vote in another party’s primary). This system differs from a true open primary because a Democrat cannot cross over and vote in a Republican party primary, or vice versa. New Hampshire requires that unaffiliated voters declare affiliation with the party whose primary ballot they select in order to vote in that party’s primary. Party affiliation can be switched back to “unaffiliated” after the election. In Colorado, unaffiliated voters must choose just one party’s ballot, but it does not change their unaffiliated status. The voter’s choice is public information.

Unaffiliated voters: Can participate.

Eight states use primaries open to unaffiliated voters: Arizona, Colorado, Kansas, Maine, Massachusetts, New Jersey, Rhode Island and West Virginia.

Note: New Mexico and New Hampshire require that unaffiliated voters declare affiliation with the party whose primary ballot they select in order to vote in that party's primary. Some analysts see this as a way for unaffiliated voters to participate in primaries, but because it requires affiliative—even if short lived—we are not considering these two states as open to unaffiliated voters in this report.

Partially Open Primaries

This system permits voters to cross party lines, but they must either publicly declare their ballot choice, or their ballot selection may be regarded as a form of registration with the corresponding party. Political parties keep track of who votes in their primaries as a means of identifying their supporters.

Unaffiliated voters: Can participate.

Six states use partially open primaries: Illinois, Indiana, Iowa, Ohio, Tennessee and Wyoming.

Open Primaries

“Open primary” states do not register voters by party, either at the time of registration or when a primary ballot is selected. In an open primary, voters may choose which party’s ballot to vote, and this decision is private and does not register the voter with that party. In this system, voters can cast a vote across party lines for the primary election. Critics argue that the open primary dilutes the parties’ ability to nominate a candidate of their choice. Supporters say this system gives voters maximal flexibility, maintains their privacy, and also may force candidates to appeal to a broader section of the electorate. 

Unaffiliated voters: Can participate.

Fifteen states use open primaries: Alabama, Arkansas, Georgia, Hawaii, Michigan, Minnesota, Mississippi, Missouri, Montana, North Dakota, South Carolina, Texas, Vermont, Virginia and Wisconsin.

“Top Two” and “Top Four” Primaries

The “top two” primary format uses a common ballot that lists all candidates on the same ballot. In California, the ballot includes each candidate’s party affiliation, whereas in Washington, each candidate is authorized to list a party “preference” but does not have to. The top two vote-getters in each race, regardless of party, advance to the general election. Advocates of the "top two" format argue that it increases the likelihood of moderate candidates advancing to the general election ballot. Opponents maintain that it reduces voter choice by making it possible that two candidates of the same party face off in the general election. They also contend that it is tilted against minor parties who will face slim odds of earning one of only two spots on the general election ballot.

California and Washington use a “top two primary”, and Alaska will use a “top four” primary for future elections. Alaska adopted this policy in 2020 when voters narrowly approved Measure 2, which also calls for the use of ranked choice voting for general elections.

Unaffiliated voters: Can participate.

Other Primary Processes

In Louisiana (LSA-R.S. 18:402), on the general election date, as set by federal law for the first Tuesday after the first Monday in November (2 U.S. Code § 7), all candidates run on the same ballot. If no candidate receives a majority of the votes (50% +1), then the top two vote-getters face a runoff six weeks later. One way to look at this process is to say there is no primary election--just a general election for all candidates, with a runoff when needed. In 2020, the Louisiana legislature enacted SCR 55, creating a Closed Party Primary Task Force to study and make recommendations about switching from the current system to a closed primary system.

In Nebraska (Neb. Rev. St. § 32-401), a partisan primary is used for members of congress and statewide office holders. Legislators, on the other hand, are elected on a nonpartisan basis, without a party designation, and with all candidates on the same nonpartisan primary ballot. The top two vote-getters advance to the general election. This system is common for local nonpartisan offices in many parts of the nation.

For information on changes made by states to their primary types, 2010 – present, see Table 2.

Section 2: The Legal Landscape for Primary Elections

Under the U.S. Constitution, the states have the power to regulate the time, place and manner of elections. As different candidate nominating systems have emerged over time, a tension has arisen between the states’ power to regulate these systems and the First Amendment rights afforded to voters as well as political parties based on freedom of association. In the last 40 years, as primaries became the dominant mechanism for political parties to identify their general election candidates, the U.S. Supreme Court has weighed in on this conflict in four notable cases concerning the constitutionality of varying state primary systems.

In Tashjian v. Republican Party of Connecticut (1986), the Court considered a challenge to a Connecticut statute that required voters wishing to participate in a party primary to be registered members of that party. In 1984, the Republican Party of Connecticut issued a rule that allowed unaffiliated voters to vote in Republican primaries for federal and statewide offices, even though state law called for closed primaries. The Republican Party then filed suit challenging the constitutionality of the Connecticut law, arguing it restricted the First Amendment rights of the Party to enter into political association with individuals of its own choosing. The District Court ruled in favor of the Party, and the Court of Appeals affirmed. The Supreme Court ruled that the First Amendment prevents a state from implementing regulations that significantly affect a political party’s right to define their membership: “The State of Connecticut's interest in preventing raiding was not sufficient basis for statute mandating closed primaries, where political party wished to open its primary elections only to unaffiliated voters and not to members of other political parties, and election statute provided that [an] unaffiliated voter could register as [a] party member as late as noon on last business day preceding primary.” This case set a precedent; from then on, the Court would heavily weight a party’s First Amendment rights as compared to a state’s interest in regulating primary elections.

The next challenge to come before the Supreme Court was in 2000, in California Democratic Party v. Jones. The Democratic Party challenged California’s blanket primary system, in which any voter could vote for a candidate regardless of party affiliation. The Court struck down the California system, reasoning that the blanket primary impermissibly burdened the party’s right to select its own representative. The Court ruled that California did not assert a compelling enough state interest; the state had offered rationales including ensuring candidates were widely represented and increasing turnout. This decision then led to the Ninth Circuit Court of Appeals invalidating Washington’s blanket primary system in Washington State Republican Party v. Washington (2006).

The Supreme Court considered a suit challenging Oklahoma’s semi-closed primary system in Clingman v. Beaver (2005). State law allowed parties to open their primaries to independent voters, but voters registered for one party could not vote in a different party’s primary. The Libertarian Party sought to open their primary to all registered voters, but the state only agreed to allow independent voters to participate in the Libertarian primary. The Libertarian Party and various voters challenged the primary statute on First Amendment grounds. The Supreme Court ruled that the “Constitution grants States broad power to prescribe the time, places, and manner of holding elections for Senators and Representatives, which power is matched by state control over the election process for state offices.” Further, “Oklahoma's semi-closed primary system, under which a political party could invite only its own registered members and voters registered as Independents to vote in its primary, did not severely burden the associational rights of the state's citizenry, so as to require application of strict scrutiny when the system was challenged as unconstitutionally burdening First Amendment right to freedom of political association.” The Court upheld Oklahoma’s semi-closed primary system, marking a departure from the previous two cases (Tashjian v. Republican Party of Connecticut and California Democratic Party v. Jones) in that the Court sided with the state and its interests in this case.

The Supreme Court again considered Washington state’s primary system in Washington State Grange v. Washington State Republican Party (2008). Following the invalidation of Washington’s blanket primary system, voters passed an initiative implementing a “top two” primary system. A challenge was soon brought by multiple political parties. The Court upheld the top two system, relying on the state’s constitutional power to regulate elections, and reasoning that the parties’ assertion of the possibility of voter confusion as to which candidate was preferred by the party was based on speculation. This case continued the trend set in Clingman v. Beaver of the Court siding with state interests in disputes over primary election systems.

Conclusion: The Supreme Court is yet to weigh in directly on the constitutionality of primary systems in which a voter can choose to participate in the party primary of their choice. In other words, whether open primaries—no matter how that phrase is defined—also bump up against the right of free association—has not been tested in the highest court yet, and lower court rulings have been inconsistent.

Section 3: Other Ways Primaries Differ Between the States

Each state’s election system is unique, and how they structure their primaries is unique as well. While a primary is likely to be run with the same ground rules as are used for general elections (when and how absentee voting is permitted, polling place standards, voter identification requirements, etc.), a number of primary-specific questions remain. 

Who is in charge of primaries, the state or the political party?

Caucuses are run by political parties, and in recent years party-run presidential primaries have cropped up. State primary elections so far have been run by the state, following state law. The cost of primary elections is borne by the state, with South Carolina as an exception, where the political parties are required to provide some funding for the primaries. (Note: presidential preference primaries have more variation than state primaries. Between 2016 and 2020, 11 states replaced caucuses with primaries.)

Must the two major parties use the same nominating system within a state?

In most states, all major parties must hold their primaries on the same day, following the same rules about who can participate and how the election will be run. For state primaries, Alaska and Idaho allow each party to determine its preferred primary process. This may be advantageous when the two parties are in disagreement about their preferences, and perhaps for the minority party in a heavily one-party state. The minority party might prefer to gather at a convention, or, as in the 2020 presidential nominating process, run a separate election under their own auspices.

In which states is a majority vote required, and thus where are primary runoffs held?

Seven largely southern states require a candidate to win a primary election with a majority of the votes: Alabama, Arkansas, Georgia, Mississippi, Oklahoma, South Carolina and Texas. If no candidate for a given office receives 50%+1 of the vote in the primary election, a separate primary runoff election is scheduled for a few weeks later. In that second election, only the top two vote-getters run, ensuring that one of them will receive a majority. (In addition, North Carolina uses runoffs with a 30% threshold; South Dakota uses runoffs only for the offices of U.S. Senator, U.S. Representative and governor; and Vermont uses runoffs but only in the case of a tie vote.) The advantage of having a majority vote requirement is that the party nominee has proven to have broad support; a disadvantage is that the state pays to run two separate elections, the primary and the runoff.

When are state primaries held, and what are the consequences of that choice?

Each state makes its own decision on when to hold its state primaries. State primaries begin in early spring and the last few are held in early September. (Primaries cannot be held any later than that because federal law requires that general election ballots be sent to military and overseas voters at least 45 days in advance of the general election; primaries held after approximately September 10 would make preparation for mailing out general election ballots to overseas voter’s problematic.)

The choice of state primary dates dictates candidate filing dates and marks the beginning of the campaign season. On average, in any two-year election cycle, one or two state legislatures move their state primary date earlier or later. To see state and presidential primary dates in 2020, see Table 3.

The Bipartisan Policy Center (BPC) recommends coordinating with nearby states to hold primaries on the same day. In fact, the BPC suggests a single national primary day for federal (congressional) primaries. The Brookings Institute also favors a national primary day. These ideas have not gained traction. Evidence from naturally occurring shared dates is correlated with a modest increase in participation, perhaps because nearby states may share media markets.

Is the presidential primary held on the same date as the state primary?

Every four years, presidential preference primaries (PPPs) are an option states can, and mostly do, use. (As recently as 50 years ago, only a handful of states had a PPP, with most state parties determining their preferred presidential candidate through caucuses or other means.)

The laws in 31 states plus D.C. call for their presidential preference primary or presidential nominating event to be held separately from (and earlier than) their state primary. (Those states are Alaska, Arizona, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Idaho, Iowa, Kansas, Louisiana, Maine, Massachusetts, Michigan, Minnesota, Missouri, Nevada, New Hampshire, New York, North Dakota, Oklahoma, Rhode Island, South Carolina, Tennessee, Utah, Vermont, Virginia, Washington, Wisconsin and Wyoming.) The perceived advantage is that states get more attention early in the season, before the candidate pool has been narrowed or the final candidate has already been determined. (In 2020, because of COVID-19, three of these states—Connecticut, Georgia and New York—moved their presidential primary later in the year to coincide with their state primary.)

The laws in 19 states call for their presidential preference primary to be held in conjunction with their state primary. (Those staes are Alabama, Arkansas, California, Indiana, Illinois, Kentucky, Maryland, Mississippi, Montana, Nebraska, New Jersey, New Mexico, North Carolina, Ohio, Oregon, Pennsylvania, South Dakota, Texas, West Virginia). This only works when the state primary is scheduled in June or earlier, in time to identify the party’s presidential preference before the summer conventions. The advantage is that one election can serve two purposes, offering significant cost savings for the state. It is likely that turnout is improved, because of the interest in the presidential race.

What relationship, if any, do primary types and Election Day registration have?

Based on a cross tabulation of states that have Election Day registration and their primary types, there is not an obvious correlation. Of the 19 states that have implemented Election Day registration:

• 2 states use closed primaries (Maryland and Nevada).
• 3 states use partially closed primaries (Connecticut, Idaho, and Utah).
• 3 states open primaries to unaffiliated voters (Colorado, Maine and New Hampshire).
• 2 states use partially open primaries (Iowa and Wyoming).
• 7 states use open primaries (Hawaii, Illinois, Michigan, Minnesota, Montana, Vermont and Wisconsin).
• 2 states use top two primaries (California and Washington).

Section 4: Ranked Choice Voting and Primaries

What is Ranked Choice Voting?

Ranked choice voting (RCV) is a vote counting system, not a primary type. In a ranked choice voting system, whether or not the election is a primary or a general election, voters rank all the candidates for a given office by their order of preference—first choice, second choice, etc. The votes are first tallied based on the first choice on every ballot. If no single candidate wins a first-round majority of the votes, then the candidate with the lowest number of votes is eliminated and another round of vote tallying commences. If a voter's first choice is eliminated, then the vote goes to the second choice on their ballot and so on. Eventually one candidate receives a majority (over 50%) and wins the election. The result is similar to traditional runoff elections, but voters make just one trip to the polls. That is why RCV is also known as “instant runoff voting.” RCV works for multi-winner elections as well.

While much of the debate about RCV is about how the system works, the underlying question is whether having elections won by a plurality—the highest vote-getter—or by a majority—over 50% of voters is preferable. A number of state constitutions are clear that a plurality determines an election’s winner; others are silent. It is up to policymakers to decide if an elected official who won based on a plurality below the 50% mark can be an effective leader. That is, will they represent the greater population or feel the need to focus only on the needs of their base?

RCV can be used in any kind of primary—open, closed, top two, etc. The vote counting system does not dictate who can participate in an election.

Some say that RCV is particularly useful in primaries. In primaries with many candidates, as was the case in the Republican presidential field in 2016 and the Democratic presidential field in 2020, RCV would mean voters could select their true first choice, and have more well-known or traditional candidates as their second, third and so on choices.

RCV could also be used to combine a primary with a general election. In Louisiana, on the general election date nominees from all parties run together, and a runoff between the top two vote getters is held the first Saturday in December. Louisiana—or any state that chose to do so—could combine the first election and the runoff election into one RCV election.

Considerations:

Section 5: Conclusion, Resources and Acknowledgements

One of the thorniest election policy concerns that state legislatures address is how primary elections, or party nominating functions more broadly, are best run. Historically, the trend (albeit a slow one) is to allow more voters to participate, but that runs directly counter to the belief that political parties are private entities and can therefore determine who participates.

In recent years, the changing complexities of the American electorate and particularly the increase in the number of voters who do not affiliate with a major party have led to more legislative interest in a full array of options.

With that in mind, this report offers a lens into the options currently used around the nation. While we have “bucketed” state primary systems based on NCSL’s taxonomy (closed, partially closed, partially open, open to unaffiliated voters, open primaries and top-two primaries), we fully recognize that the specifics of each state’s system make each state’s system unique. In other words, the categories are helpful, but not definitive.

We note, too, that new options are developing all the time. Alaska voters approved a citizens’ initiative in 2020 that creates a “top four” primary system, with the general election to be run with ranked choice voting. Louisiana, which has used a system where the nation’s general election serves as the primary, with a runoff scheduled weeks later for decades. In 2021, its legislature will be studying other options.

In fact, the state of state primaries is fluid, and one of the areas where policy is most changeable. This report is intended to provide insights for those who are thinking of future needs and not as a limited menu of options. 

This report was supported in part by a grant from the Thornburg Foundation, a family foundation that makes grants in the areas of good government reform, early childhood education, agriculture reform and community funding.

Section 6: Appendices

* No primary for state legislative seats in 2020.

** In certain circumstances, North Carolina holds a second primary. It did not do so in 2020, but those dates were either April 21 or May 12.