Credit: Tony Webster

What began as a way of trolling Prius drivers became a signature protest against America’s first black president — rolling coal. Drivers spend hundreds or thousands of dollars retrofitting their trucks so they can blanket cyclists, motorists, and pedestrians with thick, black clouds of exhaust.

“I run into a lot of people that really don’t like Obama at all,” one seller of coal-rolling equipment told Slate. “If he’s into the environment, if he’s into this or that, we’re not. I hear a lot of that.” In some instances, the practice has taken on an explicitly racial tone, as drivers publish videos of themselves rolling coal on Black Lives Matter protesters.

Why would anyone spend so much money to do something so hostile and self-defeating? New research may offer some insight.

After Barack Obama took office, white Americans were less likely to see climate change as a serious problem, according […]