The Trump administration escalated its fight with
California on Tuesday, accusing the state of failing to enforce the U.S. Clean Air Act and threatening to withdraw billions of dollars in federal highway funds to the country's most populous state.
California, which has imposed strict state standards limiting vehicle emissions in defiance of Trump's attempts to roll back regulations, has "the worst air quality in the
United States," U.S. Environmental Protection Agency (EPA) Administrator Andrew Wheeler wrote to California Air Resource Board chief Mary Nichols in a letter dated Tuesday.
EPA officials acknowledged they had not sent any similar letters to other states and denied the letter was politically motivated.