CHANGE: EPA Prepares to Gut Obama’s Signature Move on Autos.

The Obama-era rules would have required cars and SUVs to hit 55mpg by 2025, but Trump and EPA chief Scott Pruitt, both of whom have voiced public doubts about climate change, think the mark is too high and therefore problematic for manufacturers. The revised standards are still being worked out, but the Los Angeles Times notes that the move sets up a huge fight with California, which has a waiver under the 1970 Clean Air Act to set its own standards. Another dozen states, including New York, typically follow California’s lead, which the NYT notes raises the possibility of the US essentially having two auto markets, with some states—say, those on the coasts—abiding by tougher emission rules.

It’s called federalism.