State rankings

Open Primary States

Open Primary States: compare 50 US states on 4 metrics.

Primary Type

9 values across 50 entries

Congressional/State

4 values across 50 entries

Presidential

6 values across 50 entries

Data

Click a column to sort.

50 states
AlabamaOpenOpenOpenAll voters must choose one party's ballot to vote on, but they are not tied to that party. But voters who do not participate in either primary will only be given the amendments/referendum ballot.
AlaskaTop-FourOpen, All CandidatesClosedVoters may vote for one candidate per race without consideration for political affiliation. This includes nonpartisan and undeclared.
ArizonaOpen to UnaffiliatedSemi OpenClosedWhile party members may only vote on that ballot, unaffiliated voters may choose which ballot to vote on.
ArkansasOpenOpenOpenArkansas state law gives parties discretion to determine participation rules. Both the Democratic and Republican parties operate an open primary.
CaliforniaTop-TwoOpen, All CandidatesPartially ClosedAs of 2022, California is attempting a Top-Two system, where all registered voters receive one ballot regardless of party affiliation, and the top two move on to the general election.
ColoradoOpen to UnaffiliatedSemi OpenOpen to UnaffiliatedUnaffiliated voters in Colorado may vote in either party’s primary without registering with that party, but they must choose only one party ballot.
ConnecticutPartially ClosedClosedClosedOnly voters enrolled in a party may vote in that party’s primary, while unaffiliated voters may participate only if permitted by party rules and must choose a single party’s primary when multiple are held.
DelawareClosedClosedClosedDelaware voters must declare a party in advance to vote in that party's primary.
FloridaClosedClosedClosedFlorida voters must declare a party in advance to vote in that party's primary.
GeorgiaOpenOpenOpenNo partisan registration, and voters are bound to their party if there is a runoff
HawaiiOpenOpenClosedVoters may receive ballots for all parties without declaring a party preference, but they may cast votes for candidates of only one party (or the nonpartisan ballot) in the primary election.
IdahoPartially ClosedClosedPartially ClosedIdaho state law gives parties discretion to determine participation rules. The Democratic Party operates an open primary. (Open for Democratic Party)
IllinoisPartially OpenOpenPartially OpenVoters must declare a party at the polling place and can only receive that party’s primary ballot, and those who refuse to state a party cannot vote in the primary. They may also participate in a local party primary if applicable, but cannot vote in more than one statewide par…
IndianaPartially OpenOpenPartially OpenA voter may participate in a party’s primary only if they previously voted for, or intend to vote for, that party’s nominees in general elections, meaning access is tied to demonstrated party support rather than free choice at the primary.
IowaPartially OpenOpenPartially OpenAny registered voter may declare or change party affiliation at the polls on election day and then vote in that party’s primary, with the change recorded in official registration records.
KansasPartially ClosedSemi OpenPartially OpenKansas state law gives parties discretion to determine participation rules. The Democratic Party operates an open primary. (Open (Democratic Party)
KentuckyClosedClosedClosedKentucky party-affiliated voters can only vote in that party's primary.
LouisianaAll-Comers/Open to UnaffiliatedSemi OpenPartially ClosedLouisiana uses an all-comers (open) primary system, where all voters can vote for any candidate in the primary regardless of party affiliation, and the top candidates may advance or win depending on majority rules.
MaineOpen to UnaffiliatedSemi OpenOpen to UnaffiliatedUnenrolled voters may participate in a party’s primary without enrolling in that party, but they may vote in only one party’s primary election.
MarylandPartially ClosedClosedPartially ClosedA political party may choose whether to allow unaffiliated voters to participate in its primary election, meaning access for non-party voters depends on party rules rather than being uniformly open.
MassachusettsOpen to UnaffiliatedSemi OpenOpen to UnaffiliatedMassachusetts is a semi-closed primary, where unenrolled voters may choose a party’s primary ballot and registered party members vote only in their own party’s primary.
MichiganOpenOpenOpenMichigan voters do not declare affiliation but must choose a party's ballot to vote on.
MinnesotaOpenOpenOpenNo partisan registration, voters may select one primary to vote in
MississippiOpenOpenOpenMississippi voters do not declare affiliation, but they do have to choose a party's ballot to vote.
MissouriOpenOpenOpenMissouri voters do not declare affiliation, but they do have to choose a party's ballot to vote.
MontanaOpenOpenOpenMontana voters do not declare affiliation, but they do have to choose a party's ballot to vote.
NebraskaNonpartisan/OpenSemi OpenPartially ClosedRegistered voters receive ballots based on party affiliation, where party-affiliated voters get their party’s primary ballot and unaffiliated voters receive only nonpartisan ballots unless specific exceptions apply.
NevadaPartially OpenClosedPartially OpenVoters declare a political affiliation at the polling place, and while party members are restricted to their own party’s primary, certain voters—such as those affiliated with minor parties—may receive a nonpartisan ballot instead of a partisan one.
New HampshireOpen to UnaffiliatedSemi OpenOpen to UnaffiliatedUnaffiliated voters may choose a party’s primary ballot on election day and register with that party for the primary, with the option to return to undeclared status afterward.
New JerseyClosedClosedClosedVoters must be a member of a party to participate in the primary.
New MexicoOpen to UnaffiliatedSemi OpenOpen to UnaffiliatedA voter who is not affiliated with a party may choose one major party’s ballot at the primary election without changing their registration, allowing unaffiliated voters to participate in a party primary by selecting a ballot.
New YorkClosedClosedClosedVoters in New York must be a member of a party to participate in the primary.
North CarolinaOpen to UnaffiliatedSemi OpenOpen to UnaffiliatedUnaffiliated voters may choose and vote in one party’s primary by stating their preference at the polling place.
North DakotaOpenOpenDiffers by PartyAll voters receive a single primary ballot with party sections, and they may choose candidates from only one party section, with votes for multiple parties resulting in rejection of the ballot.
OhioPartially OpenOpenPartially OpenVoters may request a party’s primary ballot by declaring support for that party, but eligibility can be challenged based on the voter’s recent primary voting history and party affiliation record.
OklahomaPartially ClosedClosedPartially ClosedA political party may choose to allow independent voters to participate in its primary election, meaning unaffiliated voter access depends on party permission rather than being automatically available.
OregonPartially ClosedClosedPartially ClosedA political party may choose whether to allow unaffiliated voters to participate in its primary election, and may also limit which candidates those voters can select, meaning access for non-affiliated voters depends on party rules.
PennsylvaniaClosedClosedClosedPennsylvania voters must be registered with a party to participate in the primary.
Rhode IslandOpen to UnaffiliatedSemi OpenOpen to UnaffiliatedAll unaffiliated voters choose one party's ballot to cast their vote in the primary. This choice is viewed as a party declaration.
South CarolinaOpenOpenOpenSouth Carolina voters do not declare affiliation, but they do have to choose a party's ballot to vote.
South DakotaPartially ClosedClosedPartially ClosedA political party may choose whether to allow unaffiliated voters to participate in its primary election, and may also limit which candidates those voters can select, meaning access for non-affiliated voters depends on party rules.
TennesseeClosedOpenClosedVoters may participate in a party’s primary only if they are affiliated with that party or formally declare allegiance and intent to affiliate with it at the time of voting.
TexasOpenOpenOpenState does not have party registration.
UtahPartially ClosedClosedPartially ClosedUtah state law gives parties discretion to determine participation rules. The Democratic Party operates an open primary. ((Open for Democratic Party)
VermontOpenOpenOpenVermont voters do not declare affiliation, but they do have to choose a party's ballot to vote.
VirginiaOpenOpenOpenVirginia voters do not declare affiliation, but they do have to choose a party's ballot to vote.
WashingtonTop-TwoOpen, All CandidatesOpenWashington uses a top-two primary system, where all candidates appear on the same primary ballot regardless of party, and the two candidates receiving the most votes advance to the general election, regardless of party preference.
West VirginiaPartially ClosedClosedPartially ClosedUnaffiliated voters may participate in a party primary only if the political party allows it, while otherwise remaining limited to nonpartisan contests and public questions.
WisconsinOpenOpenOpenWisconsin voters do not have to declare affiliation, but they do have to choose a party's ballot to vote. This choice does not change their affiliation.
WyomingClosedClosedClosedAn elector must declare or change party affiliation before the primary filing period and only then may vote in that party’s primary, meaning participation is limited to voters who formally affiliate with a party.

Quick answers

Where does this open primary states data come from?
Rankodex compiles it from World Population Review and the primary sources it cites: State Primary Election Types - NCSL; Types of Primary Elections: Which Primary Can You Vote In? - FindLaw; Open primary - Ballotpedia; How States Differentiate Presidential Primaries From State Primaries - NCSL.