(CNN) Former Democratic candidate for Congress J.D. Scholten will once again challenge Rep. Steve King of Iowa in 2020, citing "unfinished business that I felt in my heart," Scholten told CNN in an interview Sunday.

Up until now, Scholten, a retired semi-pro baseball player who mounted his first campaign for office against King in 2018, has played coy about a possible 2020 rematch against King, but last week he hinted towards an imminent announcement, telling The Storm Lake Times' Art Cullen , "Let me put it this way. Last cycle we hoped to win. This cycle we intend to win."

The Sioux City-native raised eyebrows nationally after nearly unseating King in 2018, when the eight-term Iowa congressman narrowly retained his seat by a margin of 3.8 points . "We created this grassroots movement that was very people-focused, and we took a race that most national folks thought was unwinnable, and we moved the needle 24 points," Scholten told CNN Sunday. "The mindset of the district, of the voters now, is completely different than when we started two years ago."

Scholten's campaign will officially launch Monday morning, in a video narrated by "Field of Dreams" star Kevin Costner. Scholten, who played baseball in seven countries but never strayed far from Iowa at heart, says the actor was the perfect choice.

"There's a connection there ... you look at 'Field of Dreams' and, 'If you build it, they will come,' that's my campaign. We built something, and we earned the votes last time."

"I really feel that if we continue to get out there to the people, prove that we're trustworthy prove that you're going to fight for the people of your district, you're going to earn votes."

Scholten told CNN he did consider challenging Iowa Republican Sen. Joni Ernst in 2020, "but ultimately, I would have a very difficult time running for that while watching King get reelected."

King has long sparked outrage and condemnation for his incendiary comments on immigration and race, but a New York Times interview, in which, King espoused racist remarks lamenting terms like "white supremacist" being deemed offensive drew fire from both sides of the aisle, prompting Republican House Minority Leader Kevin McCarthy to strip King of all committee assignments, and leading Senate Majority Leader Mitch McConnell to tell reporters , "If he doesn't understand why 'white supremacy' is offensive, he should find another line of work."

The Iowa congressman's rhetoric was deemed radioactive enough that a request to fly aboard Air Force One with President Donald Trump during a June trip to Iowa was rebuffed by the White House. Trump was instead joined by Republican Sens. Joni Ernst of Iowa and Deb Fischer of Nebraska, while King flew commercial

For his part, Scholten told CNN that King is "divisive and selfish," adding, "it's an embarrassment that we have somebody like that." Scholten stopped short of outright calling King a white nationalist, but noted, "that we have to question a member of Congress, if they're a white nationalist or not ... if it walks like a duck, and quacks like a duck, it's probably a duck."

"I think that's what people are feeling sick of, and what they're wanting to change, and honestly, we provide a positive outlet for that. We don't necessarily run against Steve King, we run for things, and I think people really took to our campaign last time, and we continue to want to do that."

King's campaign did not respond to CNN request for comment.

As for what things Scholten would run for? He says agricultural interests would be of primary concern in his office.

"At this time, you see farmers' backs are against the wall, and we're the second most agriculture producing district in America," Scholten said Sunday. "Our farmers need somebody to fight for them, and he's not just there. ... There's a lot of folks in the agriculture community that want change. And after the election, I got approached by several of these groups, they said, 'If we would have known you were this close, we would have endorsed you.' And so that's part of the reasoning of running this race again."

His dedication to Iowa farmers, Scholten hopes, will earn him some unlikely allies in Congress.

"I'm willing to work with anybody if it's going to benefit this district," he said Sunday. "(Republican Sen. Chuck) Grassley and I actually agree a lot on agriculture ... other issues, not so much, but when it comes to fighting for the farmer, we can see eye to eye on certain things, I have no problem working with him."