It boils down to whether a compromise can be reached.
Earlier this month we learned the Environmental Protection Agency (EPA) announced plans to overhaul proposed fuel economy standards originally put in place by the Obama administration. Automakers were happy, environmentalists were not, and neither was the state of California. The most populous state in the US has for years set its own emissions standards higher than what the EPA required. This in turn forced automakers to spent more money on vehicles that met California law.
Now the Trump administration and new EPA administrator Scott Pruitt want to roll back the previous 50 mpg figure set for 2025, and were initially ready to push their plans for all 50 states. California, meanwhile, shouted "states' rights," but the EPA was having none of it. A legal battle appeared to be on the horizon. Bloomberg News, however, is reporting that the California Air Resources Board believes there's a deal to be made here. The chair of the board, Mary Nichols, said that "Reason can prevail. There's a way to get to success, unless your goal isto roll over California and not allow us to have any standards."
Essentially, Nichols indicated she's open to adjusting her state's regulations in order to make life easier for automakers – as long as California's overall emissions goals still remain intact. Some of the possible adjustments California could strike a deal on with the EPA may involve granting automakers more pollution credits for getting EV fleets up and running, as well as ride sharing programs. Another possibility would be to not hold automakers accountable for the emissions produced by power plants that provide electricity for plug-in vehicles. If there's anyone who knows the art of the deal, it'd be Trump.