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A Guide to the Primary Election Cycle in the United States

Written by MasterClass

Last updated: Oct 2, 2020 • 4 min read

Voters in the United States have the unique opportunity to vote in the same election twice—once in the primary election to determine the candidate who moves forward, and then again in the general election.



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What Are Primary Elections?

In the United States, a primary election is a pre-election in which candidates are selected to run for office. This formal primary election process, regulated since 1890, is unique to the United States and occurs on both the state and national levels.

How Do Primary Elections Work?

For voters, primary elections work in a similar way to general elections: you register to vote and, on election day, visit your polling place or, if voting absentee, mail in your ballot. Whether you can vote in a primary election, however, depends on your state and political party affiliation.

After the votes have been counted, it’s not over. In an indirect primary, these results are taken to a convention where delegates representing voters cast the final votes.

  • Many Republican state primaries are decided on a winner-take-all basis, where the candidate with the most votes receives all the delegates.
  • The Democratic primaries are usually decided by proportional representation, giving every candidate who hits a certain threshold at least one delegate. (Superdelegates, introduced by the Democratic Party in the 1980s, are unpledged and unelected delegates.) Once all of the delegates have voted, a candidate is chosen and it’s on to the general election.
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What Is the Purpose of a Primary Election?

Primary elections are elections that happen at the party-level and help political parties choose the strongest candidate to move forward. As candidates from within one party debate each other, they can grow and refine their platforms and strategies to become stronger contenders in the general election. Presidential primaries, in particular, can greatly affect a campaign.

New Hampshire typically has the first presidential primary election, and results from that one state can make or break a campaign. Candidates will campaign heavily in key primary states for the publicity and funding that can result from early primary success. Super Tuesday is the day on which the largest number of states have primary elections or caucuses, which is seen as a big milestone for which candidates will move forward and which drop out of the race.

What Is the Difference Between a Primary Election and a General Election?

A primary election is a lead-up to the general election. Although primary and general elections function similarly, the winner of the primary election does not take a seat in office, they simply advance to the next stage of voting.

An interesting exception is Louisiana, where the lines between primary and general election are blurred. In Louisiana, candidates of all parties participate in a primary election. If one candidate receives over 50 percent of the vote, they win the general election, with no further voting. If no candidate receives over 50 percent of the vote, a separate general election is held between the top two candidates.


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A Guide to the Types of Primary Elections

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Types of primaries can be categorized according to the type of general election, the requirements for voting, and the way the outcome of the election is determined.

  • Primaries can be partisan, helping a single party choose its candidate for a general election, or nonpartisan, simply narrowing the field of candidates in a nonpartisan election.
  • In a closed primary, only registered party members can vote, which promotes party unity. Connecticut, Delaware, Florida, Kentucky, Maine, Maryland, Nevada, New Mexico, New York, Oklahoma, Oregon, Pennsylvania, and South Dakota all have closed primaries for at least one party.
  • In an open primary, all registered voters can vote, which allows independents to participate. Alabama, Alaska, Arkansas, Georgia, Hawaii, Illinois, Indiana, Iowa, Michigan, Minnesota, Mississippi, Missouri, Montana, North Dakota, Ohio, South Carolina, Tennessee, Texas, Vermont, Virginia, Wisconsin, and Wyoming all have open primaries for at least one party.
  • Some states have mixed primaries (aka semi-closed primaries), where independents can vote in either primary, but registered party members must vote in their own party’s primary. Alaska, Arizona, Colorado, Idaho, Kansas, Massachusetts, Nebraska, New Hampshire, New Jersey, New York, North Carolina, Oklahoma, Rhode Island, South Dakota, Utah, and West Virginia all have semi-closed primaries for at least one party.
  • In a top-two primary, voters of all parties select one candidate per office and the top two candidates for each office advance. This is the system used in Washington and California, and in Nebraska for state legislative elections, which are nonpartisan.
  • Direct primaries allow voters to pick the candidates their party will send forward. Direct primaries were first adopted in the 1840s, and used by all but four states by 1917.
  • Indirect primaries involve voting for delegates who will then choose the candidates at a nominating convention.
  • Caucuses, or meetings where candidates are chosen for an election, were popular from colonial times and into the 19th century, but have now largely been replaced by primary elections. One notable exception is Iowa.
  • Primary runoff elections are held in some states when a candidate does not receive more than 50 percent of the votes. Alabama, Arkansas, Georgia, Mississippi, North Carolina, Oklahoma, South Carolina, South Dakota, Texas, and Vermont all hold some type of runoff election if one candidate does not receive a majority of the votes during the primary. In all other states, only a plurality of the votes is required (that is, the candidate with more votes than the other candidates goes on to the general election).

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