Romney told Obama, “People in the coal industry feel like they've been crushed by your policies. 

There is no question that the Obama administration has pursued policies that have made it harder to mine and burn coal in the United States. The Environmental Protection Agency has blocked some mountaintop mining operations in Appalachia on the grounds that dumping mine waste imperils local waterways and harms wildlife.

EPA has enacted several policies aimed at curbing air pollution and greenhouse gas emissions linked to climate change, all of which will make it more expensive to operate aging coal-fired power plants. These include a rule finalized in December that will cut mercury emissions from power plants by more than 90 percent by 2016, and proposals to curb soot and carbon dioxide from utilities.

The agency is also weighing whether to classify coal combustion residue, known as coal ash or fly ash, as hazardous waste. That will make it more costly to store and dispose of coal ash.

Republicans have described this as “a war on coal,” and just passed legislation last month to overturn several of these rules. But that bill has little chance of passage in the Senate.