Regrettably, the results of the final Des Moines Register/Mediacom Iowa Poll, released Saturday night before Tuesday’s election, differed widely from the actual vote.
The poll showed Vice President Kamala Harris leading by 3 percentage points, but former President Donald Trump won the state by 13 points. Editors here at the Register are closely reviewing that disparity.
Throughout its 81 years, the mission of the Iowa Poll has been to reflect the pure, unvarnished opinions of Iowans, without pressure or interpretation from politicians, media or others. With rare exceptions, the final Iowa Poll before elections has tracked closely with the actual vote.
For example, it accurately captured Iowans’ support for then-candidate Donald Trump ahead of the 2016 presidential election and for President Trump ahead of the 2020 election. It also reflected his widespread support ahead of the Iowa Caucuses in January, showing him with a 28 percentage-point lead two days ahead of his 30-point victory.
Register editors will work closely with pollster J. Ann Selzer, to review all methodologies and other factors that may have impacted the difference.
I’ve worked with Iowa Poll data for 20 years. As with this poll, sometimes its findings have differed from other polls and conventional wisdom.
The final poll released two days before the 2012 Iowa Caucuses showed Republican Rick Santorum, who in three previous Iowa Polls had risen no higher than 6%, leaping into third place with 15%, and if the final two days of polling had stood alone, he would have edged Ron Paul for second. The Iowa Poll alone detected a Santorum surge that eventually saw him declared winner of the certified count, edging Mitt Romney by 34 votes.
I was in the room the morning Selzer presented the latest findings to stunned editors and reporters, who immediately dug into the data to try to understand why those results differed from earlier Iowa Polls and other polls on the race. Similarly, when Selzer shared the results of this latest poll, she knew they would be met with surprise and skepticism by Register journalists and the public.
She had already pored through the data, checking whether the polling sample of 808 Iowans differed in statistically meaningful ways from other Iowa Polls. She and her assistant did a detailed walk-through of the poll’s demographic breakdowns, showing that by every measure, whether by age, party identification or rural vs. urban residents, the Iowans polled this time lined up with those in recent Iowa Polls. They did.
But this time, the poll’s results did not reflect how Iowans voted three days later.
Selzer has begun “a review to raise any plausible question of what happened” between the last night of polling on Oct. 31 and the close of polls on Nov. 5.
On Dec. 12, 1943, when editors announced the launch of the Iowa Poll, they declared, “The poll has been inaugurated as a public service to the people of Iowa so that each citizen will know what the people of this state as a whole are thinking and how they divide on each of the important topics of the day.”
In the eight decades since, the Iowa Poll has measured opinions of Iowans on everything from farm policy to traffic cameras to the quality of mental health services in the state. We want to ensure it accurately reflects the sentiments of Iowans moving forward.
Des Moines Register journalists bring that same commitment to accuracy to our work every day as we cover the breadth of news in the Des Moines metro and across Iowa, from the actions of your city council and school board to business openings, concert announcements, high school sports and the Cyclones and Hawkeyes.
Iowans have just witnessed a historic election that saw President-elect Donald Trump win our state, the Electoral College and the national popular vote. Iowa Republicans appear poised to sweep the congressional races and expand their majorities in the Iowa House and Senate. Register reporters and USA TODAY’s political coverage team will provide comprehensive coverage as Iowa legislators and the new president put together their policy agendas for 2025.
The Des Moines Register will continue to be your trusted source for unbiased news in this historic moment and beyond.
Carol Hunter is the Register’s executive editor. She wants to hear your questions, story ideas or concerns at 515-284-8545, [email protected], or on Twitter: @carolhunter.
This article originally appeared on Des Moines Register: A thorough review of the Iowa Poll has begun after 2024 election miss
