The Daily Caller cites Director for the Center for Energy and Environment Myron Ebell on the MATS rule:
Some energy advocates say the closures are a result of Obama-era regulations. “I do think Trump has ended the war on coal. Most of the plant closures were baked into utility plans once the [Mercury and Air Toxics Standards] MATS rule came out,” Myron Ebell, an analyst at the Competitive Enterprise Institute, told the DCNF. Ebell worked on Trump’s EPA transition team and is a fervent critic of Obama’s policies.
He added: “We and others fought the MATS rule. It was absolutely a shameful rule.” Ebell was referring to the 2011 Mercury and Air Toxics Standards (MATS), an Obama-era regulation that required the EPA to factor in additional “co-benefits” when evaluating a regulation’s cost compared to its expected health benefits. Obama used the rule to justify waves of regulations.