EARLIER this week Lexington stood in a grimy coal-processing plant in West Virginia, dodging thundering lorries and watching a Republican politician passionately addressing an invisible crowd on the subject of Barack Obama’s “war on coal”.

It was a curious scene in several ways. The speaker was Shelley Moore Capito, a member of the House of Representatives. The occasion was the eve of a primary contest to select the Republicans’ Senate candidate this autumn (which Mrs Capito won). The congresswoman spoke at a lectern in a smart dress, blazer and houndstooth-patterned pumps, in the centre of an empty expanse of crusty black dust and pools of filthy water. Her audience consisted of two coal-industry boosters there to offer a formal endorsement, two reporters (one of them your columnist), a clutch of campaign staff and a hired TV crew. Their satellite-truck rumbled nearby, beaming Big Coal’s endorsement of her candidacy live and free of charge to local news stations.

Mrs Capito’s theme—the need to battle “anti-coal” rules from an “overreaching” Environmental Protection Agency—jarred with the setting. Her endorsement was being filmed in Chelyan, a bleak speck of a place (a dusty riverfront, a railway line, trailer parks and car-repair shops) still recovering from a January spill of coal-cleaning chemicals several miles upriver, that left 300,000 residents of the state unable to drink or wash with tap water for some days. Chelyan is not a rich place. But several locals said that they and most of their neighbours were still buying costly bottled water to drink, distrusting official assurances that the public supply is safe.

Surprisingly, Mrs Capito’s political strategy—railing against environmental regulators in a hamlet that fears to drink its tap water—makes sense. New rules passed by state legislators to tighten water safety are too weak, grumbled David Smith, a retired miner in Chelyan, noting that storage tanks full of nasty chemicals will be inspected only once a year. But he called coal regulation a wholly separate question: there are enough curbs on coal already, he charged, churned out by an Obama government that Mr Smith sees as hostile (though he would have liked more federal aid after the January spill).

In West Virginia, coal is as much about culture as economics. Moments before Mrs Capito’s arrival in Chelyan, a battered car brought a young miner, Mark Jordan Ross, to the coal-processing plant. He came to ask about job openings but lingered to express disdain for Mr Obama (who lost all 55 West Virginia counties in 2012, an historic feat), declaring: “God gave us these mountains, He put coal in there to give us jobs.” The president would still have his office job if mining ceased, Mr Ross went on: what was West Virginia supposed to do?

Mrs Capito charged coal’s opponents with liberal hypocrisy, conjuring up an image of “folks in more prosperous parts of the country” condemning coal while sitting at their computers in one of their three houses. “What do they think powers that?” Mrs Capito complained, pausing to wave at the driver of a coal truck roaring past: “This is the real world here.”

Polling suggests that Mrs Capito will be West Virginia’s next senator, replacing Jay Rockefeller, a patrician Democrat retiring after 30 years in the Senate. Coal has already helped Republicans win the state in presidential elections since 2000, ending decades in which it was a union-organised, patronage-fuelled Democratic bastion. Voters still elect Democrats to many state-level offices: the governor is a conservative Democrat, as is the state’s other senator, Joe Manchin. But the trends are one-way: rightwards.

Mrs Capito’s Democratic opponent, Natalie Tennant, holds statewide office and calls herself a politician in the Manchin mould, condemning what she calls “President Obama’s job-killing coal regulations”. She spent the eve of her primary in Mr Manchin’s hometown of Farmington (home to the “Manchin Clinic”, owned by the senator’s family, a Manchin-owned retirement home, and a large sign depicting the senator’s grocer-grandfather, “Papa Joe”, advertising his “famous meats”). Ms Tennant’s rally was held in a volunteer fire station packed with brawny union members, local politicians and her own family, who farm nearby. Ms Tennant defended coal as one of several forms of energy with which God had blessed West Virginia, along with gas, wind and solar power. To that careful centrism she added a dose of economic populism. Ms Tennant called herself pro-coal but also pro-coal miner, vowing to defend miners’ rights to good health care and pensions, while casting her Republican opponent as an ally of heartless coal bosses. (Farmington is grimly famous as the scene of a mine disaster in 1968 that prompted a big new safety law.) Echoing Democrats nationwide, she backed a higher minimum wage and other ways to shore up a fragile middle class.

Coal and the Democratic coalition

Ms Tennant’s rally was the more folksy, from the pepperoni rolls (a local speciality) to the swallows flitting overhead. Alas for Ms Tennant, nothing can hide her big problem with coal: it divides Democrats. The party’s green supporters hate this dirtiest of fuels. Many would like to see it taxed or regulated so fiercely that it stays in the ground. New federal carbon curbs are expected next January, making it uneconomic to build coal-fired power stations. Blue-collar Democrats in coal states are aghast. As a union official in Farmington said: “Coal built the middle class here.” Plenty of big-city or college-campus Democrats don’t care.

Republican talk of a “war on coal” is exaggerated. Market forces, from cheap natural gas to dwindling Appalachian coal reserves, have so far killed more mining jobs than green rules have. But coal unites Republicans’ squabbling tribes, aligning cultural conservatives and rural voters with business bosses wary of red tape. That makes it potent fuel for the Right even as it splits the Left. Expect more blazing coal-fired stump speeches.