California’s lawsuits have targeted the administration’s policies on immigration, healthcare and education. But nowhere has the legal battle had a greater impact than on Trump’s agenda of dismantling Obama-era environmental and public health regulations. In its rush to delay, repeal and rewrite rules it considers unduly burdensome to industry, the administration has experienced significant setbacks in court. Federal judges have sided with California and environmental groups in cases concerning air pollution, pesticides and the royalties that the government receives from companies that extract oil, gas and coal from public land.