Jan 13, 2024 - Politics & Policy

Who won the last 20 years of Iowa caucuses

Data: Pew Research, Axios Research ; Chart: Tory Lysik/Axios Visuals
Data: Pew Research, Axios Research ; Chart: Tory Lysik/Axios Visuals

The Iowa caucuses have a spotty recent track record on forecasting future presidents or nominees, despite captivating the nation at the top of an election year.

Why it matters: While this year's caucuses will focus on Republicans — and who might swing a perceptible dent in former President Trump's lead —  history has some wild cards to offer.

  • Results in Iowa ultimately help with "winnowing out candidates," said Karen Kedrowski, a politics professor at Iowa State University.
  • With Trump and Biden as the expected 2024 frontrunners, the upcoming primaries will ultimately be about who obtains the GOP's No. 2 spot — and by how much.

State of play: Results in Iowa can sometimes impact the trajectory of a candidate's race, but other times have a more limited effect.

  • "There's no singular key that unlocks the nomination for either party," Matt Dallek, a professor of political management at George Washington University, told Axios.

The intrigue: The demographic makeup of Iowa Republicans likely accounted for unexpected GOP wins in Iowa in past election cycles.

  • A "very well organized, very socially conservative evangelical voting bloc" has sometimes given a boost to a socially conservative candidate "who remains an important contender but not the frontrunner," Dallek said.
  • See: Former Arkansas Gov. Mike Huckabee, former Sen. Rick Santorum (Pa.) and Sen. Ted Cruz (Tx.).

In the past five elections, Democratic winners in Iowa have been more likely to be the party's eventual presidential nominee than the Republican Iowa winners.

  • Here are some standout results from the last two decades:

2008: Barack Obama rockets

Obama stands at a lectern with a crowd behind him as he gives a speech. A sign says "CHANGE we can believe in"
Then-presidential candidate Obama addresses supporters in Des Moines, Iowa, in January 2008. Photo: Saul Loeb/Getty Images

Former President Obama's 2008 win in Iowa helped shape the rest of his campaign and eventual rise to the presidency.

  • Obama, who was a first-term U.S. senator from Illinois running a grassroots campaign, turned out first-time and independent voters in his support, per Iowa PBS.
  • That turnout helped prove his legitimacy against a more established politician, Hillary Clinton, who was third in Iowa.

Margin of win: Obama won by roughly 8 percentage points over former U.S. Sen. John Edwards (D-N.C.), his nearest opponent.

Of note: A decade later, Obama told Crooked Media as part of an oral history that winning the caucuses was the highlight of his career, making him feel like his campaign was viable.

2008: Mike Huckabee leverages religion

Mike Huckabee smiles with a small crowd arround him. In the background a sign says his first name.
Then-GOP candidate Mike Huckabee speaks to supporters on caucus night in Des Moines, Iowa in January 2008. Photo: Cliff Hawkins/Getty Images

At the time of his candidacy, Huckabee was not well-known outside his home state, Arkansas.

  • He became governor in 1996 after his predecessor's resignation, and he served in that role until 2007. He was also a Baptist preacher.

Margin of win: Huckabee won by more than nine points over his nearest opponent, then-former Massachusetts Gov. Mitt Romney.

  • The late John McCain, an Arizona U.S. senator who became the party's nominee, finished in third place.

Huckabee dropped out of the race in 2008 after the Texas primary, where he didn't do as well with conservative voters as expected, per CBS News.

2012: Rick Santorum's "upset" win

Rick Santorum stands at a microphone with people smiling behind him. A sign says his name in the background.
Then-presidential candidate Rick Santorum speaks during a rally on caucus night in Johnston, Iowa. Photo: Scott Olson/Getty Images

Santorum, a then-former U.S. senator from Pennsylvania, appealed to Iowa Republicans with socially conservative views.

Margin of win: Santorum ended up just 34 votes ahead of Romney. (Yes, really.)

  • "We feel very, very good that we not only won, but that we . pulled off a huge upset," he said at the time.

Santorum eventually got 1.5% of the national primary vote in 2012, third to Romney (93.1%) and former Texas Rep. Ron Paul (4.7%).

  • Romney, a two-time presidential candidate, became the eventual GOP nominee.

Flashback: Issues with missing precinct results in 2012 led the state's Republican Party to temporarily consider not declaring a winner.

  • Santorum's lead was officially declared 16 days following the final caucus vote. In preliminary counts, Romney had been leading.
  • Santorum ended up taking the lead in North Dakota, Minnesota, Iowa, Nebraska, Colorado, Kansas, Oklahoma, Louisiana, Mississippi, Alabama and Tennessee, before dropping out of the race in April 2012.

2016: Cruz beats Trump

Ted Cruz holds a microphone and points while giving a speech
Then-presidential candidate Ted Cruz addresses supporters in February 2016 in Des Moines, Iowa. Photo: Furlong/Getty Images

Cruz, who campaigned heavily in Iowa, focused on appealing to voters' religious beliefs, including a two-and-a-half hour rally months before the caucuses "seeking to tap into anxieties over religious persecution," per the Texas Tribune.

Margin of win: Cruz won by about four points over his nearest opponent, Trump.

  • Cruz became second to Trump nationally with 21.1% of the 2016 primary vote, versus Trump's 43.4%.

Go deeper: "Tectonic shift in power": How MAGA pastors boost Trump's campaign

2020: Mayor Pete boon

Pete Buttigieg stands at a lectern with a crowd cheering behind him. Several people wave American flags.
Then-presidential candidate Pete Buttigieg addresses supporters on caucus night in Des Moines, Iowa. Photo: Tom Brenner/Getty Images

Pete Buttigieg, at the time the mayor of South Bend, Indiana, went all over the state of Iowa to campaign, focusing on uniting political divisions and leaning on his midwestern roots. He also invested heavily in ads.

  • He was not as popular in states with more racial and ethnic diversity, and dropped out of the race in early March 2020 before Super Tuesday.

Margin of win: Buttigieg narrowly won Iowa with a lead of 0.04 over the nearest candidate, Sen. Bernie Sanders, per the state's Democratic Party. Final results came after glitches caused delays.

  • Biden was fourth in Iowa, after Sanders and Sen. Elizabeth Warren. Sanders and Warren focused their campaigns on cities and college towns, the New York Times reported.
  • Buttigieg claimed victory in Iowa before vote totals were reported.

Go deeper: Inside the GOP candidates' strategies in Iowa

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