Technically, all this was accomplished through a system in which the Environmental Protection Agency set emission standards for new motor vehicles, and granted waivers for more demanding standards.
But in 2019 the Trump administration withdrew the waiver for California’s tougher standards on cars, and the state challenged that action in court. The case, however, was not resolved, and when President Biden took office, the EPA reinstated the waiver.
Now Ohio and 16 other Republican-dominated states have sued, asserting that the waiver violates the basic design of the U.S. Constitution, which they assert should treat states as equals. Environmental groups allege that the GOP states have no intention of adopting standards that are anything like California’s regulations; rather, they contend, this is an effort to gut the Clean Air Act itself.
The D.C. Circuit Court of Appeals sided with the EPA, finding that the Constitution does not bar Congress from leaving states with different levels of sovereign authority. Now the Supreme Court will decide.
