Update: California has predictably challenged the move, and has vowed to file a lawsuit, according to Bloomberg. Governor Gavin Newsom, meanwhile, said that the White House's action was motivated by oil companies.

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The Trump administration on Wednesday revoked an Obama-era waiver allowing California to set its own standards for automobile emissions, a move which President Trump claims will lead to "significantly more jobs" and safer, less costly vehicles.

"The Trump Administration is revoking California’s Federal Waiver on emissions in order to produce far less expensive cars for the consumer, while at the same time making the cars substantially SAFER," Trump tweeted Wednesday morning, claiming that the move will result in "older, highly polluting cars" being replaced by "new, extremely environmentally friendly cars."

.... advantage, and also due to the fact that older, highly polluting cars, will be replaced by new, extremely environmentally friendly cars. There will be very little difference in emissions between the California Standard and the new U.S. Standard, but the cars will be.... — Donald J. Trump (@realDonaldTrump) September 18, 2019

....far safer and much less expensive. Many more cars will be produced under the new and uniform standard, meaning significantly more JOBS, JOBS, JOBS! Automakers should seize this opportunity because without this alternative to California, you will be out of business. — Donald J. Trump (@realDonaldTrump) September 18, 2019

The 2013 waiver issued to the California Air Resources Board (CARB) by the EPA allowed the state to mandate stricter air quality standards than those imposed at the federal level, according to NPR, which notes that the announcement comes amid a DOJ investigation into a July deal between California and four automakers, which would hold them to higher emissions standards.

The move comes after the Department of Justice earlier this month launched an antitrust investigation into a July deal between California and four automakers — Ford, Volkswagen, Honda and BMW — and is seen as a broader effort by the White House to roll back efforts to combat climate change. In the agreement between the state and manufacturers on fuel economy standards, which the administration says may be illegal, the automakers pledged to produce passenger vehicles averaging 50 miles per gallon by model year 2026, which is in line with Corporate Average Fuel Economy (CAFE) standards set by the Obama administration. -NPR

Rolling back the Obama-era guidelines will freeze mileage standards at 37 mpg from 2020 to 2026.

President Trump has directly attacked the July deal with California, saying an August tweet: "Henry Ford would be very disappointed if he saw his modern-day descendants wanting to build a much more expensive car, that is far less safe and doesn’t work as well, because execs don’t want to fight California regulators."

....that when this Administration’s alternative is no longer available, California will squeeze them to a point of business ruin. Only reason California is now talking to them is because the Feds are giving a far better alternative, which is much better for consumers! — Donald J. Trump (@realDonaldTrump) August 21, 2019

The EPA has called California's agreement with the automakers as a "PR stunt," while spokesman Michael Abboud said on Tuesday that the deal "does nothing to further the one national standard that will provide certainty and relief for American consumers." Abboud says that California officials "continually refused" to work with the Trump administration to reach a "common sense solution."

California Governor Gavin Newsom panned the move, saying in a statement that it "could have devastating consequences for our kids’ health and the air we breathe," according to NBC News.

The Union of Concerned Scientists - a nonprofit advocacy group - said in an original statement that the Trump administration is engaged in a "witch hunt against California and carmakers."

The debate over the current federal fuel economy standards dates back to well before the 2016 elections. While the auto industry reached a compromise early on with the Obama administration setting a target of 54.5 miles per gallon for 2025, the deal called for a “mid-term review” that would explore whether the target remained feasible. With the rapid shift from passenger cars to less fuel-efficient pickups and utility vehicles, a number of automakers began pressing for a rollback, a request the outgoing administration rejected. Initially, some of those manufacturers supported the Trump administration’s plan to stage its own analysis. But the preliminary revision jointly revealed by the EPA and the National Highway Traffic Safety Administration last year went well beyond what was expected, and received little industry support. -NBC News

According to California Attorney General and trump foe Xavier Becerra, "While the White House clings to the past, automakers and American families embrace cleaner cars. The evidence is irrefutable: today's clean car standards are achievable, science-based, and a boon for hardworking American families and public health."