© Copyright 2018, Des Moines Register and Tribune Co.

Iowa Rep. Steve King has cruised to victory in his last eight elections despite a long history of inciting controversy, but a new Des Moines Register/Mediacom Iowa Poll shows he may be in for a tougher race Tuesday.

On a generic ballot, 45 percent of likely Iowa voters statewide say they plan to support a Democrat for Congress and 39 percent say they will support the Republican candidate.

The poll, which questioned 801 likely Iowa voters from Oct. 30 to Nov. 2, has a margin of error of plus or minus 3.5 percentage points. Within each district, the margins of error range from plus or minus 7.4 in the 1st and the 2nd districts to plus or minus 6.6 in the 3rd and 4th districts.

► Election Day 2018 voter guide: Everything Iowans need to know before you vote

In King's 4th District, the unnamed Republican candidate leads the unnamed Democrat by 4 percentage points.

That's in contrast to Republican Gov. Kim Reynolds, who leads the 4th District by 9 percentage points in her race against Democrat Fred Hubbell.

The closest King has come to a defeat was in 2012, when former Iowa first lady Christie Vilsack waged a well-funded, competitive race in a year that President Barack Obama was on the ballot and recent redistricting worked to her advantage.

► More coverage of Iowa's 4th Congressional District

"She came within 8 points, and that was considered quite impressive," said J. Ann Selzer, president of Selzer & Co., the firm that conducted the poll. "So for us to be showing a lead for him that’s half that — it’s just something we’ve not seen before."

With the exception of his 2012 contest against Vilsack, King has won each of his other races by at least 22 percentage points.

On Tuesday, he'll face J.D. Scholten, a 38-year-old former minor league baseball player who has mounted an aggressive campaign that's raised substantially more money. Scholten's campaign issued a press release Friday saying it has raised more than $900,000 since the previous Monday.

Throughout the week before the election, controversy enveloped the King campaign after the Washington Post reported that he met with a far-right Austrian group founded by a former Nazi. King has denied that a Holocaust memorial group paid for the trip, and he has pushed back against any charges of wrongdoing.

All of that has elevated King's race against Scholten into the national spotlight. It's also sparked rebuke from some of the nation's leading Republican voices, including from U.S. Rep. Steve Stivers, R-Ohio, who chairs the National Republican Congressional Committee. Businesses including Land O' Lakes and AT&T have divorced themselves from King.

In Iowa, state party leaders have been largely silent.

► More from the Des Moines Register Iowa Poll

Democrats lead in other districts

The poll shows Democrats leading Republicans on the generic ballot in Iowa's three other congressional districts.

In the 1st District, where Democrat state Rep. Abby Finkenauer is challenging incumbent Republican Rep. Rod Blum, the unnamed Democratic candidate leads the unnamed Republican candidate 47 percent to 40 percent.

In the 2nd District, where Democrat Rep. Dave Loebsack is favored to easily hold onto his seat against Republican challenger Christopher Peters, the margin is 12 percentage points, 46 percent for the Democrat and 34 percent for the Republican.

In the 3rd District, where Republican incumbent Rep. David Young is facing Democrat Cindy Axne, the unnamed Democrat shows a 9 percentage-point lead, 48 percent to 39 percent.

► FOLLOW THE REGISTER on FACEBOOK, TWITTER, INSTAGRAM and YOUTUBE

Jill Kort is a 46-year-old registered Republican in West Des Moines who says she has begun favoring Democrats.

Kort said she’s voted for the Republican in every presidential election since she was 18. But that changed in 2016, when she voted for Democrat Hillary Clinton because she didn’t support Trump. Now, she said, she can't back Republican candidates who stand with him.

“Honestly, the Republican Party — I don’t really want to have anything to do with it anymore,” she said. “If he’s the leader, and that’s who people are identifying and supporting, I don’t want anything to do with that.”

— Des Moines Register Reporter Barbara Rodriguez contributed to this report.

ABOUT THE IOWA POLL

The Iowa Poll, conducted October 30-November 2, 2018, for the Des Moines Register and Mediacom by Selzer & Co. of Des Moines, is based on telephone interviews with 801 Iowans ages 18 or older who say they will definitely vote or have already voted in the 2018 general election for governor and other offices.

Interviewers with Quantel Research contacted 1,087 Iowa adults with randomly selected landline and cell phone numbers supplied by Survey Sampling International. Interviews were administered in English. Responses were adjusted by age, sex and congressional district to reflect the general population based on recent census data.

Questions based on the subsample of 801 Iowa likely voters have a maximum margin of error of plus or minus 3.5 percentage points. This means that if this survey were repeated using the same questions and the same methodology, 19 times out of 20, the findings would not vary from the true population value by more than plus or minus 3.5 percentage points. Results based on smaller samples of respondents — such as by gender or age — have a larger margin of error.

Republishing the copyright Iowa Poll without credit to the Des Moines Register and Mediacom is prohibited.