DAN OSBORN, a candidate for the Senate in Nebraska, has a fable he recounts on the campaign trail. First told by a Canadian trade unionist in the 1960s, Mr Osborn’s version goes like this: “It’s a story about a society of mice that happens to be ruled by cats. The mice are just like our society. They go to work every day, they send their kids to school.” And each election, they pick from a crowd of cats to rule them. Eventually, “the mice wake up”. They realise the problem: it is not that “we’re electing the wrong kind of cat”. It is that “we’re electing cats”. Mr Osborn says that what makes him different is that he is “not ashamed to admit that I’m a mouse.”

The polls suggest he has a small but real chance of becoming a very powerful rodent. In this election, Democrats seem likely to lose their tiny majority in the upper chamber. But in staunchly Republican Nebraska, Deb Fischer, the state’s senior senator, faces an unexpectedly difficult fight to keep her seat. Mr Osborn managed to manoeuvre himself into being the only other serious candidate (the Democratic Party chose not to put anybody up). He is showing that, even in red states, Republicans can be vulnerable.

Speaking in a wine bar in Ashland, a suburb wedged roughly halfway between Omaha and Lincoln, Nebraska’s two big cities, Mr Osborn jokes that he is a transplant to the state—he moved to Omaha aged seven, when his father took a job on the railways. He met his wife at high school there, and on graduating, joined the navy. He later served in the Nebraska National Guard on a tank crew, before becoming a mechanic at the Kellogg cereal factory in Omaha, and getting involved in trade unionism. On his first day, he says, an “old Polish guy” told him to join the union. By 2021 he was the local union president, and led the Omaha leg of a bitter 77-day strike at all Kellogg’s plants. After that, in his telling, he was fired—and so ended up running for office.

At the age of 49, Mr Osborn is the picture of a white working-class union man. He dresses almost exclusively in plaid shirts and jeans (claiming not even to own a suit), usually with a naval baseball cap. When he speaks, he sometimes trips over his words—referring at one point to a “Mark Zuckerburger”. Yet there are hints of metropolitanism too. His daughter is a professional dancer in Hollywood. And despite his folksy charm he is unusually willing to talk about policy in detail. One proposal is to raise the cap on Social Security contributions so that workers with high incomes pay more.

Mr Osborn has maintained a studious silence as to where he would sit in the Senate. He claims to have been a registered independent his whole life, and will not say how he will vote in the presidential election. Ms Fischer’s spokesman argues however that he is a “liberal Democrat in disguise”. Her campaign has pointed to complimentary remarks Mr Osborn once made about Bernie Sanders (he praised the socialist senator from Vermont for raising money for his strike effort at Kellogg).

Mr Osborn’s rhetoric has Bernie-ish overtones. “This is a government for the 1% and the corporations,” he said at his event in Ashland. Yet, like many Donald Trump-supporting union members, he has some conservative stances. “There’s a lot of people we don’t want here that shouldn’t be here,” he says of illegal immigration. He argues that the border crisis is in fact engineered by Republicans in Congress: “Senator Fischer’s four big donors are meat packers in this state, who benefit from a wide-open border of undocumented workers that they can choose to exploit for next to nothing.” He also stresses that, despite supporting the restoration of Roe v Wade, he is a Catholic and personally opposed to abortion.

Can it work? Nebraska is now one of America’s reddest states. But it was not always so. The state had a Democratic senator until 2013. Mr Osborn’s advisers like to point out that it was home to William Jennings Bryan, a populist three-time Democratic candidate for president in the late 19th and early 20th centuries. Like Jennings Bryan, they argue that the Republican Party represents big-business interests. And in Ms Fischer, he has an ideal opponent. She is far from populist, and is much closer to Mitch McConnell, the Republican Senate minority leader, than she is to Mr Trump. At an event for the local Republican party in Norfolk, a small town in north-eastern Nebraska, she rejected a suggestion from one member that Republicans should have been more disruptive in Congress, defending the Senate’s rules and traditions.

If Mr Osborn has a chance, it is because it is the Democratic Party itself, not Democratic messages, that have fallen out of favour, so an outsider taking on the system can win. Even if he fails—still the most likely outcome—his campaign has sent a message that the sorts of working-class voters who have flocked to Mr Trump are not yet entirely sold on his party. The next election cycle may have a few more Dan Osborns. Perhaps they will call themselves “the Mice”. ■