Last week, the Trump administration delivered a catastrophic blow to US climate policy by repealing the longstanding scientific finding that planet-warming pollution poses a danger to humans. Getting to this point was one of the administration's most audacious deregulatory goals. But it doesn't represent a complete success — yet. Now comes the years-long race through the courts to see if they really can pull off kneecapping the Environmental Protection Agency from regulating climate pollution ever again. They are facing a phalanx of opponents. Last week, more than a dozen major environmental and public health groups filed a lawsuit against the Trump administration's repeal of the greenhouse gas endangerment finding. Those organizations are setting up a high-stakes legal battle that could go all the way up to the Supreme Court. Ironically, that's the place this all began. In 2007, a major Supreme Court case, Massachusetts v. EPA, found that greenhouse gases met the definition of an "air pollutant" under the Clean Air Act, and that the EPA had the authority to regulate them. That ruling gave birth to the endangerment finding two years later. Now, environmental legal experts say, the Trump administration is hoping a far more conservative court will undo it all. If they are ultimately successful, the administration can more easily overturn other rules that reduce climate pollution emitted from power plants and oil and gas operations — and make it much harder for a future administration to put the rules back in place. Read more at the link in @cnnpolitics’ bio. 📷: Jon Cherry/Getty Images; Evan Vucci/AP