“It’s not a poorly written rule so much as a muddled one that conflates those two too readily,” Competitive Enterprise Institute energy policy analyst William Yeatman said in an interview.

“Instead of taking a subcategory of an industry, it took two disparate industries, combined them together, and then said the best system of emissions control technology for a coal-fired power plant is to be a gas-fired power plant,” Yeatman said.

Environmental advocates argue coal is on the decline in any case.

“Everybody who follows these issues knows the real reason coal use has gone down is because natural gas has become cheaper and so much more abundant,” O’Donnell said. “The EPA rules on the new sources would have no affect on that situation because, as far as I know, there’re no new coal plants in the works anyways.”

But Yeatman and others say it would be folly to over-rely on natural gas.

“There’s this misconception that there’s been this wholesale shift from coal to natural gas,” Yeatman said. “There’s only one region where natural gas has competed with the price of coal, and that’s in the southeast. In the rest of the country coal’s about twice as cheap.”