Independent Voter Project

U.S. Primaries


Prior to legal analysis of primary election laws, it is imperative that we have a strong understanding of definitions used to refer to each type and component of a primary election. Often times, public discussion has misused or misplaced terminology that can lead to confusion even among those well versed in primary election law. It is essential that we clearly define these particular terms in light of the Constitutional considerations that arise from each.

For example, the term “open” refers to the access, herein defined, that a voter has to vote for the candidate(s) of his or her choice. But “open” is not a complete term. An “open primary” can be conducted for a partisan purpose, or a nonpartisan purpose. A “partisan open primary” can be conducted using a single ballot (AKA “blanket open primary”), or a separate ballot for each party, whereas a “non-partisan primary” may only be conducted on a single ballot.

For an overview and legal analysis of the basic components of different types of primary elections, read: How Do Primary Elections Work?

For the more in-depth information on the legal frameworks associated with primary elections throughout the United States, see: Generally Applicable Federal Law

History of Primaries

Primary elections did not become popular within the United States until the early 20th century. Even now, primary elections are not common among other democracies. Primaries were adopted to address the issue of party bosses choosing candidates in “smoke-filled rooms.” Primaries were to give the citizens a greater say in which candidates made it onto the general election ballot. As time has progressed, the primaries have gained great importance in deciding the ultimate outcome of general elections. Because of gerrymandering efforts, often general elections are decided based upon the outcome of the primary election. Despite this, many states have primary systems which either partially or totally bar participation from unaffiliated voters, who are becoming a larger and larger portion of the U.S. population. Additionally, these primaries are funded from tax dollars. Parties have successfully asserted their private rights implicated by the primary election process. See, e.g., California Democratic Party v. Jones, 530 U.S. 567 (2000).

Types of Primaries

Nonpartisan (purpose: winnow the number of candidates)

Top Two Primary

In a Top Two Primary, all candidates running for an office are listed on one ballot, regardless of their party preference. A candidate’s party has no impact on how the election is conducted or who is allowed to advance to the General Election. Instead, candidates go on to a run-off election based solely on how many votes they receive in the Primary .


Jungle Primary

In a jungle primary, if one candidate receives over 50% of the votes, that candidate is elected, and no other election occurs. If no candidate receives over 50% of the votes, a general runoff election is held between the top-two vote-getters, regardless of party affiliation.


  • Louisiana

Partisan (purpose: select a representative of a political party)

Open Primary

In an open partisan primary, any registered voter may request a ballot from one political party that has qualified for a primary election. That ballot only has the potential candidates for that particular party.


  • Alabama
  • Arkansas
  • Hawaii
  • Michigan
  • Montana
  • Minnesota
  • Mississippi
  • Missouri
  • North Dakota
  • Wisconsin
  • Virginia
  • Vermont
  • Virginia
  • Wisconsin
  • Montana

Closed Primary

In a closed primary election, only voters registered with a political party that has qualified for a primary election may vote. They may only vote on ballots for their registered political party.


  • Colorado
  • Connecticut
  • Florida
  • Iowa
  • Kansas
  • Kentucky
  • Maine
  • Nevada
  • New Hampshire
  • New Jersey
  • New Mexico
  • New York
  • Pennsylvania
  • Rhode Island
  • Wyoming

Semi-closed Primary

In a semi-closed primary election, political parties that have qualified for a primary election may choose to allow unaffiliated voters to vote on their ballot. This is a choice left up to the parties.


  • Arizona
  • Idaho
  • Maryland
  • Massachusetts
  • Nebraska
  • North Carolina
  • Oklahoma
  • Oregon
  • South Dakota
  • Utah
  • West Virginia

Semi-open Primary

Although conducted like an open primary, voters must make some public declaration of support for a political party before they may receive its ballot.


  • Georgia 
  • Illinois
  • Indiana 
  • Ohio 
  • South Carolina 
  • Tennessee 
  • Texas


Alaska – Alaska is unique because it uses two types of primary election systems. It combines a blanket partisan primary, where all political parties candidates are listed on a single ballot which any voter may vote on, and a semi-closed primary. This is because in Cal. Dem. Party v. Jones, the blanket partisan primary was found unconstitutional if parties were forced to participate. In Alaska, all parties except for the Republican Party have chosen to participate in the blanket partisan primary. The Republican Party has its own semi-closed primary.