In the final days before midterms, in a sleepy farm district in ruby red Trump country, the re-election campaign of Iowa Rep. Steve King has become a surprise electoral bellwether for Democrats’ chances of retaking the House. King, one of the most hard-line Republicans in Congress, was last elected for his eighth term in 2016 with 61 percent of the vote; in 2016, Donald Trump won his county by 27 points. Yet as of Monday, his lead against Democratic challenger J.D. Scholten has narrowed to just one point.

A combination of factors have complicated King’s once-dominant electoral position. For one, Trump’s extreme rhetoric on immigration has turned up the temperature in midterm races across the country, forcing Republicans to take increasingly controversial positions on issues like child detention, militarizing the U.S. border, and birthright citizenship. In the past week alone, two domestic terrorists appeared to take inspiration from the president’s fear-mongering about migrants “invading” the southern border: one who sent pipe bombs to a dozen high-profile critics of Trump, and a neo-Nazi who killed 11 people at a synagogue in Pittsburgh. In both cases, the suspects were Trump supporters obsessed with conspiracies involving Democrats such as George Soros, who Trump and his allies in Congress have suggested is funding or encouraging the migrant “caravan” making its way through Mexico toward the U.S. In the wake of those episodes, a Gallup poll found Trump’s approval rating had dropped to 40 percent, the lowest it’s been since the summer, when he implemented his controversial family-separation policy.

Perhaps more important, King has become increasingly vocal about his own racial politics. In July 2016, while Trump was busily campaigning, King said during an MSNBC panel discussion that “white people” had “contribute[d] more . . . [than] any other subgroup of people” to civilization—prompting shocked reactions from his fellow guests. Since the election, however, he seems emboldened. Earlier this month, he endorsed an outright white nationalist running for mayor in Toronto, calling her “Pro Western Civilization and a fighter for our values.” Most recently, King told an Austrian nationalist Web site that America must “defend Western civilization” against immigrants, lest the country “become subjugated by the people who are the enemies of faith, the enemies of justice.”

The combined effect seems to be backfiring for King, who suddenly faces the toughest race of his political career. In September, his lead over Scholten narrowed to 10 points; on Monday, a survey by Change Research found that margin had closed to just a single point—a 26-point swing since King’s 2016 re-election. To be sure, several of his constituents told The Washington Post they weren’t bothered by his views. “I don’t see him as racist. I don’t know. He’s just Steve,” said his longtime acquaintance, Crawford County Supervisor Eric Skoog, who condemned King’s views on immigration and has personally worked on integrating migrant children into local schools. But for others, King’s barely veiled white nationalism is a bridge too far. “The comments, I mean they’re all over the place,” Republican voter Raymond Beebe told The Guardian last weekend. “‘All uneducated immigrants smuggle drugs,’ ‘black people could afford abortions if they stopped buying iPhones,’ ‘no group has done better for the country than the white people’—he’s so openly racist, and I find that very abhorrent.”

Which of these stances wins out at the polls is difficult to say. After all, King’s views are common knowledge in Iowa’s 4th, which has continued to re-elect him even as he’s become more extreme. Moreover, Change Research’s results may not reflect the real attitudes of the voters surveyed, who aren’t likely to say on record that they support a known racist, even if they plan to vote for him. Either way, the sudden, unexpected competition for King’s seat suggests that support for far-right politics has its limits—and provides further evidence that voters’ queasiness with Trumpian politics is benefiting his opponents. As Politico reports, public and private polling—to say nothing of TV spending figures—shows Democrats have retaken the momentum in their quest to seize the House, especially in the final days before the November 6 election. King’s weakness is the racist canary in the coal mine.