If Donald Trump is elected president (or even if he is not elected but the Supreme Court says he is president, anyway), he is going to get a lot of pushback from the states on many issues, especially climate change. Gov. Gavin Newsom (D-CA) is already getting ready to take the lead at pushing back. Due to the nature of the federal system, the president has only limited power to order the states around, especially if Congress is not on board and he has to act using executive orders.
For example, Newsom made a deal with Stellantis last week in which the company, the fourth largest automaker in the world, will meet California's stringent emission standards. So even if Trump relaxes them, Stellantis will still be bound by its agreement with California. There are many other things Newsom can do and is doing. For example, in the area of off-shore drilling, which the federal government controls, Newsom could get the state legislature to pass a law requiring companies doing so to have a massive insurance policy to clean up the mess if something goes wrong. There would be endless lawsuits about it and companies would be hesitant to drill until they were all settled. That could take years. Trump isn't the only one who understands that delay is a useful legal tactic.
The state of California buys a lot of stuff, and Newsom wants to make sure it buys only from companies that comply with California's rules and regulations, which are often stricter than the federal ones. It is unlikely that the Supreme Court would want to establish a principle that the federal government can tell states who they can buy stuff from, because the next Democratic president might have some ideas about purchases by the state of Alabama, among others.
Another tactic is using the courts to slow Trump down. California AGs Xavier Becerra and Rob Bonta sued Trump 136 times when he was president. In more than half the cases, they got at least a partial win. Newsom is also working with the California Air Resources Board to create regulations that will be robust in the worst case. CARB is pushing the EPA to grant all the Clean Air Act waivers it has requested. These would limit pollution from locomotives, trucks, tugboats, and even lawn mowers. If Trump tries to roll back permissions that the government has granted up to 2029, again, there will be court fights. In most cases, the regulations would stay in force until the Supreme Court ruled on them, and that could take years. (V)