Renowned Pollster J. Ann Selzer said Tuesday she would be reviewing her data to determine why a Des Moines Register/Mediacom Iowa Poll released just days before the election produced results so far out of line with former President Donald Trump's resounding victory.

Trump handily won Iowa for a third time, defeating Vice President Kamala Harris by 14 percentage points with more than 90% of the vote counted ― a sharp contrast to Saturday's Iowa Poll that had Harris leading by 3 points.

"Tonight, I’m of course thinking about how we got where we are," Selzer, president of Selzer & Co., which conducts the Iowa Poll, said in a statement.

"The poll findings we produced for The Des Moines Register and Mediacom did not match what the Iowa electorate ultimately decided in the voting booth today. I’ll be reviewing data from multiple sources with hopes of learning why that happened. And, I welcome what that process might teach me."

The final poll showed Harris leading Trump, 47% to 44%. It had a margin of error of plus or minus 3.4 percentage points, meaning Harris' lead was within the margin of error.

Trump ultimately cruised to an easy victory Tuesday night. With 87 of 99 counties reporting results through the Iowa Secretary of State's website Tuesday evening, Trump had garnered 56% of the vote over Harris' 42%.

When the Iowa Poll was released, many dismissed it as an outlier. Other polling in Iowa showed Trump with a clear lead.

But Selzer has long been considered the gold standard pollster of Iowa, and the results Tuesday represented a rare miss in her assessments of the Iowa electorate.

From 2008 through 2020, the poll accurately reflected the winner of the presidential race in Iowa.

And in 2016 and 2020, the Iowa Poll was one of only a few in the country that accurately assessed Trump's strength going into Election Day. Each poll showed Trump winning the state by 7 percentage points — almost exactly on par with his 9-point 2016 win and his 8-point 2020 victory.

Although Selzer said she planned to do a deeper look into the data, there were a few things she was eyeing Tuesday night.

"Technically, the poll had some 'give' in that neither candidate reached 50%," she said. "So, the people who said they had voted/would vote for Robert F. Kennedy, Jr. could easily have switched to Donald Trump. The late deciders could have opted for Trump in the final days of the campaign after interviewing was complete. The people who had already voted but opted not to tell our interviewers for whom they voted could have given Trump an edge."

The Iowa Poll showed Kennedy, who had ended his presidential bid but was still on the ballot, got 3% of the Iowa vote. Fewer than 1% said they would vote for Libertarian presidential candidate Chase Oliver, 1% said they would vote for someone else, 3% weren't sure and 2% didn't want to say for whom they already cast a ballot.

"Maybe I can gain clarity on that 9% and an underlying disposition toward the presidential race," Selzer said.

Brianne Pfannenstiel is the chief politics reporter for the Des Moines Register. She is also covering the 2024 presidential race for USA TODAY as a senior national campaign correspondent. Reach her at bpfann@dmreg.com or 515-284-8244. Follow her on Twitter at @brianneDMR.