Steve King, Iowa’s most noxious politician, looks vulnerable

GIVING OFFENCE is Steve King’s stock-in-trade. The congressman for Iowa’s fourth district has suggested heaven is off-limits to gay people, spoken up for white supremacy and posed with Marine Le Pen, Geert Wilders and other far-right populists. He has likened immigrants to animals. Many are smugglers, he once said, adding that migrant men have “calves the size of cantaloupes” from lugging bales of drugs. A decade before Donald Trump proposed walling up the border, Mr King was America’s leading xenophobe. He even posed in Congress with a model of a concrete barrier topped with electrified wires. Zap foreigners, he said, to keep ’em out.

Rural Iowans have swooned at that, and at how he has enraged urban, liberal folk. His admirers say that in person he is charm itself. After nine election victories, usually by huge margins, he has seemed entirely secure. In some counties he takes over 70% of the votes, thanks to a base of conservative Christians—Dutch Reform, evangelical, Catholic and Lutheran. They like his opposition to abortion, even in cases of incest or rape. He has also picked up protest votes. As family farms have died and home towns have dwindled, Mr King’s rage at the modern world seemed fitting.

And yet, after 17 years, he looks vulnerable. Republican leaders no longer coddle Mr King. Corporate donors are...