Since 1972, the Iowa Caucus had been the first—and some argue most important—electoral test on the road to each party’s presidential nomination. That changed for the Democrats when the party voted in February 2023 to reorder its 2024 presidential primary, replacing Iowa with South Carolina in the leadoff spot as part of a major shake-up meant to empower minority voters.

"The Democratic party looks like America, so does this proposal," said Jaime Harrison, chair of the Democratic National Committee at the party's February 4, 2023 conference.

The Republican party, meanwhile, continues to kick off its presidential primaries in Iowa.

The reason why Iowa had gone first for decades started with the 1968 Democratic Convention.

The lead up to the 1968 convention had been tumultuous. The Vietnam War was in its 14th year, both Martin Luther King Jr. and presidential candidate Robert Kennedy were assassinated that spring and President Lyndon B. Johnson had withdrawn from the race in March, deciding against seeking another term. That April, Hubert Humphrey—Johnson’s vice president—jumped into the race. Humphrey’s public support of Johnson, specifically regarding the Vietnam War, upset many anti-war protestors.

While Democratic political leaders filed into the convention hall, protestors brutally clashed with police right outside its doors, with television broadcasting the political divide to the nation. Hubert Humphrey would go on to win the Democratic nomination (over George McGovern and Eugene McCarthy) despite not winning a single primary, highlighting for many the disparity between public opinion and the political process.

Eager to repair the damage from the 1968 primary campaign, Democratic party leaders formed the McGovern-Fraser Commission. The commission’s job was to improve the nomination process so voters would have a direct say as to who would be their nominee for president, ensuring that party leaders would no longer work behind closed doors to manipulate the process. State party leaders had to give 30 days notice before hosting primaries or caucuses, encouraging full participation.

Iowa’s long nominating process, featuring four statewide events (the caucuses, followed by conventions at the county, congressional district and state levels), combined with the 30-day notice required for events, meant it needed a bit of a head start, and an early slot on the voting calendar.

The first candidate to draw the nation’s attention to the Iowa Caucus was Jimmy Carter in 1976. Carter’s campaign had neither the visibility nor the money to compete in bigger state primaries early in the electoral season, so they put in a great effort to win Iowa. While many of Iowa’s Democratic voters officially remained uncommitted, Carter’s surprisingly strong finish provided some much-needed momentum. Carter was able to capitalize on the media attention he garnered to propel himself forward, ultimately winning the Democratic presidential nomination and then the presidency.

Since then, Iowa remained a crucial proving ground for nearly every presidential candidate. But the state had a spotty record of picking the president. Among Republicans since 1980, the winner of the Iowa caucuses has won the presidency just once: George W. Bush in 2000. Among Democrats, only Carter in 1976 and Barack Obama in 2008 placed first among the candidates and eventually captured the White House.

In 2020, snafus in the vote-counting process stalled the release of Iowa's Democratic primary results for nearly a week. Pete Buttigieg pulled off a thin victory, but the chaotic process diminished enthusiasm for the state's premier place in the primary line-up among many Democrats.