As expected, via GCC:
US EPA and DOT propose freezing light-duty fuel economy, GHG standards at 2020 level for MY 2021-2026 vehicles; 43.7 mpg for cars; 50-state solution
California's reply can be found here:
Governor Brown, Attorney General Becerra, and California Air Resources Board: At Every Turn, We Will Defend Our Nation’s Clean Car Emissions Standards
. . . “For Trump to now destroy a law first enacted at the request of Ronald Reagan five decades ago is a betrayal and an assault on the health of Americans everywhere,” said Governor Brown. “Under his reckless scheme, motorists will pay more at the pump, get worse gas mileage and breathe dirtier air. California will fight this stupidity in every conceivable way possible.”
“The Trump Administration has launched a brazen and unlawful attack on our nation’s Clean Car Standards. The California Department of Justice will use every legal tool at its disposal to fight back,” said Attorney General Becerra. “Our nation’s Clean Car Standards save consumers thousands of dollars, protect our families’ health, and ensure that we continue tackling climate change, the most important global environmental issue of our time. We are ready to do what is necessary to hold this Administration accountable.”
“At first glance, this proposal completely misrepresents costs and savings. It also relies on bizarre assumptions about consumer behavior to make its case on safety,” said California Air Resources Board Chair Mary D. Nichols. “CARB will examine all 978 pages of fine print to figure out how the Administration can possibly justify its absurd conclusion that weakening standards to allow dirtier, less efficient vehicles will actually save lives and money. Stay tuned for further comment. Meantime, California remains fully committed to a rigorous 50-state program with a full range of vehicle choices. That program is in effect right now and will remain so for the foreseeable future.”
Additional statements from Attorneys General across the country are available. . . .
CARB's website seems to be having issues today, as it's very slow.