The left opposes revoking the waiver, arguing that the move will harm the environment and is unlikely to hold up in court.

“In announcing on Wednesday his determination to revoke California’s longstanding authority to set its own air pollution standards, President Trump finds himself arrayed against the plain language of the Clean Air Act, California’s historical role as a laboratory for tough new environmental rules and the express wishes of several major automakers and two-thirds of the American people.” (Editorial Board, New York Times)

The right supports revoking the waiver, arguing that it is counterproductive and contrary to the law.

“Congress, understandably not wanting automakers to have to comply with 50 different sets of regulations, has generally preempted state regulation in this area — with the exception that California, and California alone, may apply for a waiver to create its own emission rules to address 'compelling and extraordinary conditions.’... [the waiver] was intended as a reference to smog. And in contrast to Californian smog, there is nothing compelling and extraordinary about Californian climate change. Climate change is happening to the rest of the country (and indeed the world) too…

“The waiver needs to go. And the Trump administration should continue with the other element of its plan too: nixing Obama-era rules that required fuel economy to hit nearly 55 miles per gallon on average by 2025, a far-fetched goal that could force car companies to sell electric vehicles at a loss to bring down the average fuel economy of their overall fleets… It’s important to note that nothing in either policy change stops companies from making more fuel-efficient cars if Americans want to buy them… It’s fine for car companies to go above and beyond what’s legally required of them. But the government should not force the industry to meet unreasonable standards, force customers to pay for it, or allow California to set national policy.” (The Editors, National Review)