The 2024 Iowa Republican presidential caucuses were held on January 15, 2024, as part of the Republican Party primaries for the 2024 presidential election. 40 delegates to the 2024 Republican National Convention were allocated on a proportional basis. As in past primary cycles, the Iowa caucuses were the first-in-the-nation Republican presidential nominating contest.

The results were a landslide victory for Donald Trump, with his 30-point margin being the largest margin of victory ever for a non-incumbent in the Iowa Republican caucuses. Trump won 20 delegates, Ron DeSantis won nine, Nikki Haley won eight, and Vivek Ramaswamy won three. Trump also became the first Republican ever to win a contested Iowa caucus with a majority of the vote, and the third person of either major political party to do so (the others being Tom Harkin in 1992, and Al Gore in 2000). Analysts described the results as establishing him as the Republican Party's presumptive nominee, with both DeSantis's and Haley's campaigns being seen as heavily damaged.

Trump also won 98 out of Iowa's 99 counties, losing Johnson County to Haley by a single vote. Ramaswamy announced the suspension of his campaign the night of the caucus, endorsing Trump, but retained his three delegates. Asa Hutchinson, who finished with less than 1% of the vote, dropped out the following day and endorsed Haley. DeSantis dropped out the following weekend and endorsed Trump.

Background and electorate History of the Iowa caucus Beginning in 1972, the Iowa caucuses have been characterized as the first major electoral test for Republican presidential contenders. Despite its strategic importance, between 1976 and 2016, only three out of eight winners of the Iowa caucuses went on to receive the Republican presidential nomination.

Republican electorate It has been argued that the Iowa Republican caucuses effectively serve as "referendums on who is the most socially conservative candidate" in the Republican field.

Commentators have noted in the 2010s the decisive role of Evangelical Christian caucusgoers in past contests. The victory of social conservatives George W. Bush, Mike Huckabee, Rick Santorum, and Ted Cruz in the 2000, 2008, 2012, and 2016 Iowa caucuses, respectively, was credited to their strong support among evangelical voters.

In 2016, it was noted by The Des Moines Register that almost half of likely Republican caucusgoers self-identify as evangelical or born-again Christians. In the 2016 Iowa Republican caucus, Senator Ted Cruz of Texas defeated eventual nominee Donald Trump by a 27.6% to 24.3% margin in what was considered an upset victory.

Procedure Delegates are proportionally allocated to candidates based on the statewide vote. Unlike most states, there is no minimum threshold for a candidate to be eligible for delegates.

Campaign developments In February 2023, the Trump campaign announced its Iowa campaign staff, with state representative Bobby Kaufmann and consultant Eric Branstad, the son of former Governor Terry Branstad, serving as senior advisors. In March 2023, Trump's campaign announced that it would hold an "America First Education Policy" event in Davenport on March 13, marking his first official campaign appearance in the state.

Nikki Haley had held 22 events in Iowa by May 19, 2023. Her campaign made ad buys of $10 million in Iowa and New Hampshire beginning in December 2023. On December 8, Haley addressed a convention center conference where she stated her campaign had momentum and needed "to have a good showing in Iowa. I don’t think that means we have to win, necessarily, but I think that we have to have a good showing."

Governor of Florida Ron DeSantis held a pair of events in the state on March 10 and was accompanied by Governor Kim Reynolds. Reynolds remained neutral between Trump and DeSantis, which caused Trump to post on Truth Social accusing her of stealing the race from him and that like DeSantis, she would not have been elected without Trump's help. Reynolds broke her neutrality in November 2023 and endorsed DeSantis. Between October and December, DeSantis toured all 99 Iowan counties. In December, DeSantis' wife, Casey DeSantis, was widely criticized for calling on Republicans from other states to participate in the Iowa caucuses.

Asa Hutchinson focused most of his energy campaigning in the state, hoping to perform well and use that success as a springboard for the rest of his campaign.

Endorsements

Polling

Aggregate polls Source of pollaggregationDatesadministeredDatesupdated RonDeSantis NikkiHaley AsaHutchinson VivekRamaswamy DonaldTrump Other/Undecided Margin270toWin270toWin January 11–15, 2024 January 15, 2024 15.7% 18.5% 0.8% 6.8%52.5% 5.7%Trump +34.0FiveThirtyEightFiveThirtyEight Through January 14, 2024 January 15, 2024 15.8% 18.7% 0.7% 6.4%52.7% 5.7%Trump +34.0RealClearPolling January 5–14, 2024 January 15, 2024 15.7% 18.8% 0.8% 6.8%52.5% 5.4%Trump +33.7Average 15.7% 18.7% 0.7% 6.7%52.6% 5.6%Trump +33.9 Poll source Date(s)administered Samplesize Margin DougBurgum ChrisChristie RonDeSantis LarryElder NikkiHaley AsaHutchinson MikePence VivekRamaswamy TimScott DonaldTrump Other UndecidedTrafalgar GroupTrafalgar GroupJan 12–14, 20241,092 (LV)± 2.9%––19.3%–18.5%0.7%–6.5%– 52.1%–2.9%Selzer & Co.Jan 7–12, 2024705 (LV)± 3.7%––16%–20%1%–8%– 48%3%5%Insider AdvantageInsider AdvantageJanuary 11, 2024850 (LV)± 4.3%––17%–17%0%–7%– 51%–8%Suffolk UniversitySuffolk UniversityJan 6–10, 2024500 (LV)± 4.4%––13%–20%0%–6%– 54%––CiviqsCiviqsJan 5–10, 2024433 (LV)± 6.4%–4%14%–14%0%–8%– 55%2%3%InsiderAdvantageInsiderAdvantageDec 18–19, 2023850 (LV)± 4.36%–4%15%–17%0%–8%– 50%–6%Fox BusinessFox BusinessDec 14–18, 2023804 (LV)± 3.5%–3%18%–16%0%–7%– 52%1%2%Emerson CollegeEmerson CollegeDec 15–17, 2023420 (LV)± 4.7%–4%15%–17%0%–8%– 50%–6%CBS News/YouGovDec 8–15, 2023478 (LV)––3%22%–13%0%–4%– 58%––Iowa State University/CiviqsIowa State University/CiviqsDec 8–13, 2023438 (LV)± 6.0%–4%17%–15%1%–7%– 54%0%2%Selzer & Co.Selzer & Co.Dec 2–7, 2023502 (LV)± 4.4%–4%19%–16%1%–5%– 51%2%3%Trafalgar GroupTrafalgar GroupDec 1–4, 20231,091 (LV)± 2.9%2%4%22%–19%1%–5%– 45%–1%Morning ConsultMorning ConsultNov 1–30, 2023 324 (LV)–1%2%18%–11%0%–13%5%50%––Iowa State University/CiviqsIowa State University/CiviqsNov 10–15, 2023432 (LV)± 4.3%1%3%18%–12%0%–6%2% 54%0%4%Arc InsightsArc InsightsNov 9–14, 2023800 (LV)± 3.5%1%4%17%–17%<1%–5%– 44%2%9%Fabrizio, Lee & AssociatesFabrizio, Lee & Associates Nov 9–12, 2023600 (LV)± 4.0%1%5%19% -16%0% -4%5%43%0%7%2%5%20% -18%0% -5% -44%0%7%Trafalgar Group (R)Trafalgar Group (R)Nov 3–5, 20231,084 (LV)± 2.9%4%5%18%–15%0%–5%9% 44%0%1%Morning ConsultOct 1–31, 2023 324 (LV)–1%2%15%–7%0%3%9%6%57%––Public Opinion StrategiesPublic Opinion StrategiesOct 24–26, 2023400 (LV)± 4.9%1%2%20%–12%1%1%4%5% 46%––Selzer & Co.Selzer & Co.Oct 22–26, 2023404 (LV)± 4.9%3%4%16%–16%1%2%4%7%43%2%3%Fabrizio, Lee & AssociatesOct 17–19, 2023600 (LV)± 4.0%2%3%21%0%14%0%2%4%5%42%2%6%Iowa State University/CiviqsIowa State University/CiviqsOct 6–10, 2023425 (LV)± 6.1%0%2%17%0%11%0%1%5%4%55%2%1%Morning ConsultMorning ConsultSep 1–30, 2023 316 (LV)–1%5%13%–6%–7%9%7%53%––CBS News/YouGovCBS News/YouGovSep 15–24, 2023458 (LV)± 6.1%0%1%21%0%8%1%6%5%6%51%0%–Public Opinion StrategiesPublic Opinion StrategiesSep 19–21, 2023400 (LV)± 4.9%1%2%21%–9%0%2%5%6%45%–9%Fabrizio, Lee & AssociatesFabrizio, Lee & AssociatesSep 17–19, 2023500 (LV)± 4.4%1%5%15%–13%<1%2%5%5%45%<1%7%Trafalgar Group (R)Trafalgar Group (R)Sep 14–18, 20231,079 (LV)± 2.9%4%2%16%0%8%0%4%7%7%49%1%2%Fox BusinessFox BusinessSep 14–18, 2023813 (LV)± 3%2%3%15%<0.5%11%<0.5%3%7%7%46%3%2%Emerson CollegeEmerson CollegeSep 7–9, 2023357 (V)± 5.1%3%–14%–7%–3%7%8%49%6%–CiviqsCiviqsSep 2–7, 2023434 (LV)± 5.8%2%3%14%–10%0%1%9%6%51%1%–Public Opinion StrategiesSep 5–6, 2023400 (LV)± 4.9%1%3%22%–6%1%2%6%5%45%––Morning ConsultAug 1–31, 2023 341 (LV)–1%4%15%–6%0%6%8%7%52%0%1%Fabrizio, Lee & AssociatesFabrizio, Lee & AssociatesAug 25–28, 2023500 (LV)–2%3%18%<1%10%1%2%7%7%44%<2%5%Public Opinion StrategiesPublic Opinion StrategiesAugust 24, 2023400 (LV)± 4.9%1%1%21%–11%1%2%7%7%41%––Public Opinion StrategiesAug 19–21, 2023400 (LV)± 4.9%3%3%14%–3%<1%2%10%3%42%––HarrisXAug 17–21, 20231,120 (LV)–2%3%11%0%4%0%3%9%8%45%3%12%–2%4%21%1%6%1%8%18%15%–4%19%Echelon InsightsEchelon InsightsAug 15–17, 2023800 (LV)± 4.2%2%4%17%–2%<1%3%8%3%33%3%14%Selzer & Co.Selzer & Co.Aug 13–17, 2023406 (LV)± 4.9%2%5%19%–6%–6%4%9%42%1%5%The Trafalgar Group (R)The Trafalgar Group (R)Aug 14–16, 20231,126 (LV)± 2.9%3%4%16%1%5%1%4%6%13%42%3%3%New York Times/Siena CollegeNew York Times/Siena CollegeJul 28 – August 1, 2023432 (LV)± 5.9%1%<1%20%<1%4%<1%3%5%9%44%<2%12%––39%––––––55%–4%Manhattan InstituteManhattan InstituteJul 2023625 (LV)–3%4%17%0%5%1%4%6%10%42%1%7%Morning Consult July 1–31, 2023 350 (LV)– 1% 2% 19%– 4% 0% 4% 8% 5%55%– 2%National ResearchNational ResearchJul 23–24, 2023500 (LV)± 4.4%3%4%15%–3%0%2%5%9%42%–13%Fox BusinessFox BusinessJul 15–19, 2023806 (LV)± 3.5%3%3%16%<1%5%1%4%6%11%46%1%4%co/efficientco/efficientJul 15–17, 20232,238 (LV)± 2.6%–3%16%–3%–3%5%10%46%–10%National ResearchNational ResearchJul 5–6, 2023500 (LV)± 4.4%–3%21%–2%1%3%3%7%44%–14%Morning Consult June 1–30, 2023 317 (LV)– 0% 1% 18%– 2% 1% 7% 3% 3%64% 0% 1%McLaughlin & AssociatesMcLaughlin & AssociatesJun 10–12, 2023500 (LV)± 4.4%––19%–––6%–9%51%–15%––33%––––––60%–7%National ResearchNational ResearchJun 5–7, 2023500 (LV)± 4.4%–2%24%–4%0%4%1%5%39%–21%Victory InsightsVictory InsightsJun 3–6, 2023450 (LV)± 4.9%–3%21%–5%–5%2%6%44%3%12%––32%––––––49%–19%WPA IntelligenceWPA IntelligenceMay 30 – June 1, 2023655 (RV)–––29%–6%<1%4%4%7%39%–11%––43%––––––45%–12%Morning Consult May 1–31, 2023 300 (LV)––– 17%– 5% 0% 8% 5% 1%60% 4% 0%McLaughlin & AssociatesMcLaughlin & AssociatesMay 23–25, 2023400 (LV)–0%1%24%1%4%1%5%2%7%50%3%4%––36%––––––54%–11%Emerson CollegeEmerson CollegeMay 19–22, 2023600 (LV)± 3.9%0%–20%–5%1%5%2%3%62%2%–National ResearchNational ResearchMay 9–11, 2023500 (LV)± 4.4%––26%–6%1%4%3%1%44%–11%––33%––––––45%–22%McLaughlin & AssociatesMcLaughlin & AssociatesApr 27–30, 2023500 (LV)± 4.4%–1%20%1%5%0%7%2%1%54%5%5%––22%––––––57%––Morning Consult Apr 1–30, 2023 294 (LV)––– 20%– 4% 0% 7% 4% 0%60% 3% 2%Victory InsightsVictory InsightsApr 10–13, 2023400 (LV)± 4.8%––24%–14%4%–3%–54%1%–––59%–24%5%–8%––4%–––41%––––––59%––CygnalCygnalApr 3–4, 2023600 (LV)± 3.9%––30%–5%1%2%2%1%37%3%19%J.L. PartnersJ.L. PartnersMar 25 – April 4, 2023628 (LV)± 3.9%––26%–5%–3%1%–41%10%14%––39%––––––47%–15%Morning Consult Mar 1–31, 2023 329 (LV)––– 27%– 5%– 7%– 0%57% 2% 2%Morning Consult Feb 1–28, 2023 281 (LV)––– 25%– 6%– 9% 0% 0%52% 8% 0%Morning Consult Jan 1–31, 2023 367 (LV)––– 27%– 5%– 9%– 1%51% 5% 2%Morning Consult Dec 1–31, 2022 227 (LV)––– 35%– 2%– 11%– 1%44% 8% 0%WPA IntelligenceWPA Intelligence Nov 11–13, 2022 508 (LV) ± 4.4%––48%–––––– 37%– 16%WPA Intelligence Aug 7–10, 2022 508 (LV) ± 4.4%–– 37%––––––52%– 12%Neighborhood Research and MediaNeighborhood Research and Media Jun 22 – July 1, 2022 546 (LV) ± 4.2%–– 17%–2%–2%––38%4% –Victory InsightsVictory Insights Mar 5–8, 2021630 (RV) –––4%–6%–8%––61%13%–––20%–10%–19%–––33%–

Results

Just minutes after the caucus events started at 7 pm local time, Trump was projected to win the most votes by the Associated Press. Trump received 20 delegates, DeSantis nine, Haley eight, and Ramaswamy three. Barring any shifts in votes after the conclusion of the Iowa Republican Party's ongoing recanvass of the caucus results, Trump won all of Iowa's counties except for Johnson County, which he lost to Haley by one vote.