"WASHINGTON — Monday’s surprise move by General Motors, Toyota and other auto giants to back President Trump in his fight with California over pollution rules came after days of White House pressure to support one of the administration’s biggest efforts to weaken climate regulations.
Previously, many automakers had indicated to California that they would not take a stand, according to Mary D. Nichols, chairwoman of California’s clean air regulator, the Air Resources Board.
Late last week, their stance quickly changed.
Andrew Olmem, a top policy aide to Mr. Trump, began calling car companies to push them to sign on to the administration’s effort in the courts to eliminate California’s right to set its own auto emissions rules on planet warming pollution, a power granted under the Clean Air Act of 1970. He was joined on the phone in some cases by Justice Department officials, according to a person familiar with the matter."