Every four years, Americans select a president. Election 2024 officially kicks off this month with the Iowa caucuses on January 15. At press time, nine candidates were still vying for the Republican

Jim McMahon
Primary Matters
The presidential election is about to get underway. Here’s how the major parties choose their candidates.
How did this system come about?

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Joe Biden
President; seeking a second term
In the 19th and early 20th centuries, elected officials and party leaders chose presidential candidates without public input. Reformers began promoting primaries—elections to pick party nominees—saying party bosses were cutting backroom deals to select nominees. The first primaries occurred in the early 1900s, but it wasn’t until after World War II that they began to play a significant role in choosing candidates.
What are primaries?

Official White House photo by Shealah Craighead
Donald Trump
Former President
A primary works very much like a general election. On dates selected by each state, the District of Columbia, and territories such as Puerto Rico and Guam, voters head to polling places to cast secret ballots. Based on the results, the state parties allocate delegates for each candidate to their national conventions, where presidential nominees are formally chosen. To win the nomination, a candidate must win a majority of the delegates at the party’s convention.
How are caucuses different?

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Ron DeSantis
Governor of Florida
Some states, like Iowa, have caucuses rather than primaries (see map, above). In caucuses, party members meet at the district or
What’s the role of the conventions?

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Nikki Haley
Former Governor of South Carolina
In most recent elections, a candidate from each party has collected enough delegates in the primaries to all but guarantee the nomination. This has turned the conventions into little more than three-day-long TV ads for the candidates since the actual tallying of votes is just a formality. The last time there was a convention fight to win the majority of delegates’ support was in 1976, when President Gerald Ford narrowly beat Ronald Reagan to win the Republican nomination.
Why have Iowa and New Hampshire traditionally been so important?

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Vivek Ramaswamy
Entrepreneur
Since 1952, New Hampshire has held the first presidential primary in the nation. During the 1970s, the Iowa caucuses, which take place earlier, began to gain importance, especially as a potential springboard for upstart candidates.
In recent years, other states have threatened to move their votes ahead of Iowa’s and New Hampshire’s, arguing that those states—which are small, rural, and less diverse than the country as a whole—shouldn’t wield so much influence over the process of choosing the president.
With that rationale in mind, the Democratic Party has this year chosen South Carolina, which has a significant Black population, to hold the first primary. (To complicate matters, New Hampshire has a state law saying it must hold the nation’s first primary, so it intends to ignore the order set by party leaders.) The Democrats are also moving Michigan, which is a key swing state, earlier in the primary calendar.
Being early in the voting lineup gives a state influence on the process—and a big dose of attention and

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1980
Ronald Reagan wins New Hampshire, ending doubts about his candidacy.

Courtesy of the White House Historical Association
1988
After a poor showing in Iowa, George H.W. Bush sweeps the South, including Texas, and becomes the front-runner.

Official White House Photo by Pete Souza
2008
Barack Obama handily wins the Iowa caucuses, defeating Democratic front-runner Hillary Clinton.

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2020
Joe Biden’s big win in South Carolina rescues his struggling campaign. For 2024, Democrats moved South Carolina’s primary date earlier to give the state more influence.
Key Dates
March 5
Super Tuesday
Voters in 16 states cast ballots.
July 15-18
Republican National Convention
Milwaukee, Wisconsin
August 19-22
Democratic National Convention
Chicago, Illinois
November 5
Election Day