It's difficult to predict when, how or whether the federal government will wield any tools of preemption to bar cities and states from enforcing their own environmental rules. Nonetheless, governments across the country are bracing for new restrictions. California's decision to hire Obama's attorney general, Eric Holder Jr., showed it's preparing to fight for state rights in court.
"Everything is speculative right now," said Cooper Martin, a sustainability official at the National League of Cities, which represents cities in state capitols and on Capitol Hill. Based on Trump's anti-environmental cabinet nominees and his rhetoric on climate change, which he has falsely called a hoax, Martin said fears of federal preemption are "certainly well founded."
"It's just the nature of the political landscape that this hasn't been an issue on climate, at least in the last eight years," Martin said, referring to the length of Obama's presidency. "It was certainly an issue prior to that."
Clean car rules in California, which are unpopular with oil companies and auto manufacturers, offer what may be the clearest opportunity for federal preemption. Other rules that could be blocked relate to appliance efficiency standards, power plant pollution, fossil fuel exports and safe disposal of pharmaceuticals. Local governments that have spent federal transportation funds on cycling and transit initiatives could be prevented from doing so in the future.