Mitt Romney is stepping up a favorite Republican attack line in battleground states: President Barack Obama’s overzealous Environmental Protection Agency is killing jobs.

The GOP presidential nominee is telling voters in Colorado, Nevada, Ohio and Virginia that Obama’s EPA is to blame for wiping out the coal industry. Romney and his surrogates are warning Iowans of EPA plans to regulate for farm dust and railing against the agency for flying airplanes over livestock operations to spy for dirty water.

(Also on POLITICO: Mitt visits coal country)

In many instances, Romney’s EPA attacks stretch the boundaries of what the agency actually does or can do. The EPA has repeatedly denied any plans for new farm dust rules, and the planes have been used as a cost-cutting enforcement measure dating back to the George W. Bush administration. Energy experts say the coal industry’s problems are a byproduct of all-time lows in natural gas prices rather than new air pollution requirements that have been subject to legal battles for more than a decade.

But the Romney campaign is betting that public perception won’t factor into complicated realities of energy and environmental policy. Romney stood out as a moderate during primary season when his GOP rivals threatened to kill the Nixon-era agency entirely, but his attacks have picked up in the homestretch to November.