Trump Urged to Take California’s Hands Off Wheel on Emissions

California and the Trump administration are on a collision course over auto-efficiency regulations that could lead the White House to deploy the nuclear option: revoking the state’s cherished power to set its own limits on air pollution.

Environmental Protection Agency Administrator Scott Pruitt signaled he would keep California in check as the federal government reviews fuel-economy rules and said the state shouldn’t be allowed to play an outsized role in the process.

“Federalism is not one state dictating to the rest of the country what should occur,” Pruitt said. While California can regulate greenhouse gas emissions at the state ...