It was an event billed as the smackdown between the baddest coal baron around and the environmental heir to the liberal Kennedy legacy, live on stage and in the heart of Appalachia mine country. Stage right, appropriately, was Don Blankenship, chairman of Massey Energy, a meaty impassive presence, his Kentucky drawl never picking up speed or volume. On the left, Robert F Kennedy Jr, who has spent his life defending waterways, making lawyerly argument out of staccato bursts of statistics.

The pairing at the University of Charleston was the perfect personification of America's deep divides: Republican versus Democrat; old industry v new, global warming denier v impassioned advocate for climate change laws.

The battle in Thursday night's debate was over mountaintop removal mining, which blows the tops off mountains to get at thin seams of coal and of which Blankenship is the most notorious promoter. "This is the worst environmental crime that ever happened in our history," began Kennedy. "It is a crime, it is a sin, and it is a moral obligation to stop this from happening."

Companies such as Blankenship's are detonating the explosive equivalent of a Hiroshima every week, Kennedy said. They are ruthlessly anti-union and no longer provide jobs: 90,000 were shed in West Virginia over the past 50 years. Worse, Kennedy revealed, Massey's own records show 12,000 violations of pollution regulations last year. It paid $20m (£12.4m) in environmental fines in 2006.

But this was too many facts for Blankenship. "It's a bunch of rhetoric and untruths," he returned. "This industry is what made this country great. If we forget that, we are going to have to learn to speak Chinese." Or accept early deaths, he argued, noting that expectancy in Angola is 39 years.

Or, as he suggested later in a digression on poverty in India, go through life with the indignity of not having a toilet. Or, maybe just roll over and give in to the terrorists. "The truth of the matter is that were it not for coal we wouldn't have the freedom to sit up here and ­discuss this," Blankenship said.

The views – and debating styles – were a stark vision of the separate ­political realities in America.

in 2008. In 2004, he personally spent $3 million on attack ads on a judge's election.The Obama administration and its supporters – and not least Kennedy himself – got a painful message from that other reality this week. The Senate seat left by the death of his uncle Ted Kennedy was filled by Scott Brown, the first Republican in more than 50 years to represent Massachusetts in the Senate. The election takes away the Democrats' filibuster-proof majority, making it even harder for Obama to deliver on his campaign pledges to tackle global warming.

And that suits Blankenship just fine. "When you criticise what we do as an industry, you are criticising the people that are teaching your Sunday school, that are coaching your little league," Blankenship said, folksily. Worryingly for Kennedy, it got the loudest applause.

Kennedy, rallying, argued that the future was green: "If we don't switch to renewables right now we are going to be buying green technology from the Chinese for the next 100 years, the same way we have been buying oil from the Saudis for the last 100 years."

But Blankenship was still looking to the past. "Coal is what made the industrial revolution possible. If windmills were the thing to do, if solar panels were, it would happen naturally."

Oh, and global warming was a hoax, he finished. "Anyone who says they know what the temperature of earth is going to be in 2020 or 2030 needs to be put in an asylum because they don't. This whole thing is designed to transfer wealth from the US to other countries."

The university made sure the 1,000-strong audience was evenly split. On television afterwards, environmentalists said they were sure Kennedy won. The miners gave it to Blankenship: Kennedy just had too many facts from all over the place, said one.

The debate changed few minds. Ed Welch, the university president and moderator, summed it up neatly: "I don't think there is a need for an altar call to recognise any conversions."