Do Iowa Caucus winners go on to earn their party's nomination for president? What we found

All eyes of the political world are on Iowa this month for the Iowa Caucuses, the first litmus test for a crop of Republican candidates vying to be their party's nominee for president in the 2024 general election.

But with the future role of the caucuses in doubt, at least on the Democratic side, it's worth asking: How predictive are the Iowa Caucuses, anyway? Do the winners typically go on to win their party's nomination? Or the White House?

Winning the caucuses doesn't guarantee the nomination, of course. Pete Buttigieg won the Democratic caucuses in 2020, but Joe Biden was his party's nominee instead. The most recent time it did work was four years earlier: Hillary Clinton won the caucuses and went on to be her party's nominee.

The caucuses are like the first quarter of a football game: You can win without scoring the first points of the game, but the odds say victory is more likely if you do. Similarly, candidates who finished the caucuses in first place won their party's nomination more often than candidates who came in any other place.

Not counting 1972 and 1976, when "Uncommitted" technically won first place, the winner of the caucuses has gone on to earn the party's nomination roughly half of the time. That number goes up when you factor in incumbents who faced primary challenges, such as Jimmy Carter in 1980.

But candidates as far back as fourth place in Iowa have rallied to win their party's nomination: Biden in 2020, Republican John McCain in 2008 and Democrat Bill Clinton in 1992 — although the 1992 caucuses were a foregone conclusion with Iowa's own U.S. Sen. Tom Harkin running. Nobody who finished fifth or below has ever won their party's nomination for president, let alone the presidency.

Biden and Clinton both eventually won the presidency, meaning just as many candidates became president after finishing fourth in the caucuses as those who came first.

Longtime caucus supporters likely will tell you the process isn't about identifying the next president — it's about narrowing the field. A common phrase around this point in the caucus cycle is "three tickets," meaning that candidates need to finish in the top three in Iowa to earn their party's nomination. (It's also the name of the Register's podcast series on the history of the caucuses.)

After Biden's nomination in 2020, perhaps it's time to add a ticket to that count. Or perhaps his relatively poor showing in Iowa was the result of a cluttered field of candidates, and the conventional wisdom will return with fewer candidates on this year's Republican slate.

After all, the current Republican frontrunner, former president Donald Trump, held a lead in the most recent Iowa Poll that was larger than any candidate held in 2020.

Another way of looking at the Iowa Caucuses' predictive power is by co-opting one of the terms frequently used in the last caucus cycle: "viability." In the 2020 Democratic caucuses, caucusgoers whose chosen candidate did not earn 15% of the support in their precinct were required to choose a different candidate.

As it turns out, 15% is just about the minimum percentage of the vote that an eventual nominee has earned on caucus night, outside of the Harkin-tilted 1992 caucuses.

McCain earned just over 13% of the caucus vote in 2008, but won the Republican nomination. George H. W. Bush did the same in 1988 with less than 19% of the vote. And Biden won the Democratic nomination in 2020 despite earning slightly fewer than 16% of the state delegate equivalents.

Each overcame deficits of at least 10 percentage points in Iowa to win their party's nomination and, for the latter two, the presidency.

With several candidates hovering just above 15% in the latest Iowa Poll, that number could once again prove to be the threshold of viability in the caucuses.

So, does winning the Iowa caucuses ensure nomination? No. But it certainly doesn't hurt, and when caucus night rolls around, candidates will be eager to get their first points on the metaphorical board.

Tim Webber is a data visualization specialist for the Register. Reach him at, and on Twitter at @HelloTimWebber.

This article originally appeared on Des Moines Register: Iowa Caucuses: Do winners usually go on to earn their party nomination?