If Donald Trump had come to California earlier this week, and found smog conditions similar to those that prevailed here only a few decades ago, it’s easy to imagine what he would have done: tweeted about the “Sad Dem Smog!” and promptly set up an e-commerce site selling MAGA-branded catalytic converters and air filters.

Instead, Trump, who on Tuesday held fund-raisers in Silicon Valley and Beverly Hills, enacted a different form of eco-trolling, when he promised on Wednesday to cite San Francisco for the environmental damage that its homeless population has caused. On a roll, the following day, he made good on a yearlong threat to deny California the right to continue setting its own, more stringent tailpipe-emissions standards, which the state has had since Nixon first granted it the authority, as part of the Clean Air Act, in 1970. In a joint statement by the E.P.A. and the Department of Transportation, the Trump Administration also withdrew permission for California to require carmakers to offer zero-emissions vehicles, a prerogative enshrined in Obama’s 2013 Clean Air Act. Back then, the mandate was designed to stimulate innovation, for our collective salvation; in these dark ages of retrograde, reactionary American climate policy, it served only to provoke a gaslighting, gas-loving President who’s determined to turn back time.

On Friday, California, as it has become accustomed to doing, sued the Administration in an effort to preserve the state’s legacy rights surrounding emissions standards and clean vehicles. (Twenty-three other states and three cities joined the suit, which was filed in federal court in D.C.) “The environment is California’s foreign policy,” Gavin Newsom, the governor of California, told me on Thursday, as the complaint was being finalized. “It’s where we assert ourselves on the international stage, not just the national stage.” This is the sixtieth lawsuit that California has filed against the Trump Administration and, according to Newsom, by far the most consequential. “We have the law on our side, we have the facts on our side, we have science on our side, and we have moral authority—not just the formal authority—to fight back,” he told me.

It’s a fight that California has to win. Cars, trucks, and buses are America’s largest contributors to global warming, and California has the largest auto market in the United States. The reason the state has been aggressive on tailpipe emissions is not because it is the home to countless Tesla-driving eco-snobs but because it is the place where the problem first presented itself most acutely. The toxic coincidence of sunshine, cars, and mountainous terrain meant that by the late nineteen-sixties California’s air quality was the worst in the United States. Now, of the country’s ten most-polluted metropolitan areas, seven are in California.

California’s solutions are providing a template for similarly polluted and carbon-dependent economies to emulate. China has created zero-emissions-vehicle policies based on California’s mandate; the Chinese government has said that, by 2025, it wants a fifth of all cars sold there to be electric. In July, California negotiated with four automakers—Ford, Honda, BMW, and Volkswagen, which represent thirty per cent of U.S. new car sales—to establish a fifty-one-miles-per-gallon standard for all the cars they sell by 2026. Trump is seeking to cap that figure at thirty-seven miles per gallon in 2021. Earlier this month, his Department of Justice opened an antitrust investigation into the automakers’ California deal.

Newsom said, “If we’re at an inflection point in climate policy, then this issue of tailpipe emissions—from an air-quality perspective, from a public-health perspective, and from a greenhouse-gas perspective—is the game-changer. Transportation is the biggest sector of consequence. We can lament Paris, we can lament the clean-power plan he’s overruling, we can lament other initiatives, like the one on pesticides, but this is the big issue. If we’re not successful, it’s about adding a massive amount of particulate matter, increasing smog, worsening our climate crisis, massively increasing fuel costs to consumers, killing jobs, and killing America’s competitiveness internationally by harming the auto industry.”

Newsom says that the latest assault on California’s climate leadership is borne of desperation, and depends on junk science and a shoddy legal argument. I asked him if it could challenge the extent of California’s power to define a climate future in spite of Trump. “It’s a test on the limits of his power, absolutely,” Newsom said. “Because of the power, scale, and scope of the state and its influence with clean cars, he’s met his match. He’s discovering the limits of his power and authority.”

Trump’s adversarial stance is helping to shape California’s twenty-first-century identity as the Resistance State. In its shadow, Trump’s insecurities grow: the leader of the free world can’t control his unruly golden child. “It’s Nancy Pelosi’s California, it’s Adam Schiff’s California,” Newsom said. “It’s a frustrating place for him to be, and a frustrating time for the President.” Newsom went on, “We’re running historic surpluses, and he’s running historic deficits. We’re outperforming him as a nation-state in G.D.P. growth, and he’s despised here. We’re the most un-Trump state in America. He suffers the incredulity of not winning the popular vote. He lost it because of California disproportionately. He’s been rejected by Hollywood in the past. He’s a man scorned.”