King’s loss in Iowa’s Republican primary contest marks the beginning of the end for the provocative lawmaker who for years had been a conservative lightning rod in Washington for his hardline views on issues ranging from immigration to abortion.
Republican National Committee Chairwoman Ronna McDaniel tweeted early Wednesday that King's "white supremacist rhetoric is totally inconsistent with the Republican Party, and I'm glad Iowa Republicans rejected him at the ballot."
Rep. Alexandria Ocasio-Cortez, D-N.Y., tweeted, "Goodbye, Rep. Steve King. You are certainly not the only white supremacist in federal government, but you were among the most prominent. It’s a shame Republicans held you up as long as they did."
The Iowa Republican has more recently become a pariah in his own party as more mainstream GOP lawmakers distanced themselves from his more extreme views and statements.
King was stripped of his committee assignments in 2018 for comments appearing to question the criticism of white nationalism.
In November 2018, King drew a strong rebuke from the chairman of the National Republican Congressional Committee after comments relating to white nationalists and supremacists.
King had publicly endorsed a white nationalist candidate for mayor in Toronto. The candidate, Faith Goldy, has promoted books espousing anti-Semitic ideas and defending the white supremacist “14 words” slogan, according to the Toronto Star.
He also faced backlash for comments questioning whether humanity would exist anymore if not for rape and incest throughout history.
"What if we went back through all the family trees and just pulled out anyone who was a product of rape or incest? Would there be any population of the world left if we did that?" King said last August at the Westside Conservative Club in Urbandale, Iowa, according to the Des Moines Register. "Considering all the wars and all the rapes and pillages that happened throughout all these different nations, I know that I can't say that I was not a part of a product of that."
King also has drawn criticism for posts on Twitter, such as in 2017 when he wrote that “culture and demographics are our destiny” and said we “can't restore our civilization with somebody else's babies.”
And in September 2018, King came under renewed scrutiny after traveling to Austria and giving an interview in which he said: “If we don't defend Western Civilization, then we will become subjugated by the people who are the enemies of faith, the enemies of justice.”
In 2013, he commented that while he has some sympathy for some undocumented immigrants, "they aren't all valedictorians, they weren't all brought in by their parents -- for everyone who's a valedictorian, there's another 100 out there who weigh 130 pounds and they've got calves the size of cantaloupes because they're hauling 75 pounds of marijuana across the desert."
In a statement sent out shortly after his victory, Feenstra thanked King for his time in Congress and said he was focused on keeping the seat away from the Democrats come November.
“I thank Congressman King for his decades of public service,” he said. “As we turn to the General Election, I will remain focused on my plans to deliver results for the families, farmers and communities of Iowa. But first, we must make sure this seat doesn’t land in the hands of Nancy Pelosi and her liberal allies in Congress.”
The rejection of King does not mean that the Democrats are assured of picking up another seat in Congress come November, as establishment Republicans suggest the state's lone GOP-held U.S. House seat will likely remain in the party's hands with Feenstra’s win, while a King primary victory would have jeopardized the seat by setting up a rematch with the Democrat who came within 2 percentage points of beating him two years ago.
King was also vastly outspent by Feenstra and conservative groups backing him, including one-time King backer National Right to Life, and the U.S. Chamber of Commerce, the nation's largest business lobbying group.
Feenstra will face Democrat J.D. Scholten in November.
The Associated Press contributed to this report.