Trump to revoke California's tailpipe waiver

The Trump administration is set to formally revoke California's tailpipe waiver under the Clean Air Act on Wednesday, according to a source with knowledge of the change.

The move is a major strike in the ongoing battle between the Trump administration and California over the state's right to enact more stringent air pollution standards due to its poor air quality.

It would come as Trump is fundraising in California, a state that has been a hotbed of resistance to his administration where Hillary Clinton won more than 4 million more...