California Has a Posse in Tug-of-War With Trump Over Electric Cars- Mary Nichols & Ann Carlson

Yet having more states line up with California could affect the outcome, said Ann Carlson, a law professor at the University of California at Los Angeles. If electric-car sales rise as more states require them, manufacturers could have a harder time arguing that compliance costs are too high. And the states that are requiring zero-emission car sales are doing so not just to fight climate change but to limit toxic pollutants like soot and smog, as required by the Environmental Protection Agency itself. 

“States are relying on the zero-emission standard to comply with federal law,” Carlson said, “and the federal government is trying to undercut their ability to do that.”