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Primary Elections: Types, Rules & State-by-State Guide

66,187,949

Americans are registered to vote in states that won't let them vote in primary elections.

They pay for these elections with their taxes. They just can't participate.

PRIMARY TYPES

Not All Primaries Are Created Equal

Six systems. One question: who gets to vote?

The further right on this spectrum, the more voters can participate.

Closed15

Only party members can vote. Independents excluded.

Semi-Closed10

Unaffiliated voters can pick a party ballot. Registered members of other parties can't cross over.

Semi-Open3

Any voter can request a party ballot, but the choice may be recorded.

Open20

Any voter can vote in any party's primary. No registration required.

Top-Two2

One ballot, all candidates, all voters. Top two advance.

Top-Four1

One ballot, all candidates, all voters. Top four advance to ranked-choice general.

Only three states (California, Washington, and Alaska) have moved past the party primary model entirely.

In most of America, the primary is the real election. When one party dominates a district, whoever wins the primary wins the seat. Lock voters out of the primary, and you've locked them out of choosing their representative.

ALL 51 STATES

Where Does Your State Fall?

Each dot is a state. The further right, the more of its voters are independent.

0%10%20%30%40%50%60%70%National Avg: 30.2%AL 8.72%FL 30.25%CT 43.89%AK 64.71%
THE FIX

IVP Pioneered the Fix. Three States Proved It Works.

The nonpartisan primary puts every candidate on one ballot and lets every voter participate. No party registration required.

Election Day in a Closed Primary State

You arrive at the polls.

Are you registered with a party?

No → You don't get a ballot. Go home.

Yes → You get your party's ballot. Only your party's candidates.

Election Day in a Nonpartisan Primary State

You arrive at the polls.

Here's your ballot. Every candidate is on it.

Vote for whoever you want, regardless of party.

The top finishers advance to the general election.

In a closed primary, two separate party ballots, only registered members can vote. Independents get nothing. The candidates who advance are chosen by the smallest, most partisan slice of the electorate.

15
states lock independents out

29% of all states use the most restrictive primary model.

66.2M
voters in closed-primary states

They fund these elections with their tax dollars.

30.2%
of all voters are independent

The largest voter bloc in America, and the one with the least access.

FAQ

Frequently Asked Questions

A primary election is the first round of voting that narrows the field of candidates before the general election. In most states, primaries are organized by political party: each party holds its own primary to choose its nominee. In nonpartisan primary states, all candidates compete on a single ballot.

Traditional Primary
Party A Ballot → Party A Members Only → Party A Nominee
Party B Ballot → Party B Members Only → Party B Nominee
Independents: No Ballot
Nonpartisan Primary
One Ballot
All Candidates, All Voters
Top Finishers Advance

It depends on the state. In open primary states, any voter can participate regardless of party registration. In closed primary states, only registered party members can vote; independents are shut out entirely. Semi-closed states typically let unaffiliated voters choose a party primary, while keeping registered members of other parties from crossing over.

In an open primary, any registered voter can vote in any party's primary without being a member of that party. In a closed primary, you must be a registered member of a party to vote in its primary. The practical difference: in closed primary states, the tens of millions of Americans who register as independent cannot vote in the elections that often determine who holds office.

In a growing number of districts across the country, the general election is not competitive: one party dominates. That means whoever wins the primary wins the seat. When primaries are closed, a small group of partisan voters effectively chooses the representative for the entire district, including the independents who were locked out of voting.

A nonpartisan primary puts all candidates on a single ballot and lets every registered voter participate, regardless of party. Instead of separate Democratic and Republican primaries, voters choose from the full field. The top finishers advance to the general election. California and Washington use a top-two system; Alaska uses top-four with ranked-choice voting in the general.

The number varies depending on how you classify "open." Roughly 20 states have fully open primaries where any voter can participate in any party's primary. Another 10 or so have semi-closed or semi-open systems that give unaffiliated voters some access. Three states (California, Washington, and Alaska) have moved beyond the party primary model entirely with nonpartisan systems.

WHAT YOU CAN DO

The Primary System Doesn't Have to Work This Way

IVP has been fighting to open primaries to every voter since 2010. We wrote the law that changed California. We're taking the fight to more states. You can help.

Stay in the fight.

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Primary election classifications and voter registration data sourced from L2 voter file (2026). Independent voter counts include unaffiliated, no-party-preference, and third-party registrations. Approximately 20 states use L2 modeled party estimates rather than official party registration data. Turnout figures based on voting-eligible population (VEP) from the UF Election Lab.