Newman was kicked out in a recall in June 2018 with 58% against, and replaced by Chang. Newman beat Chang in 2016 by 2498 votes. (Chang did not technically run against Newman in the recall -- the vote was an up or down against Newman, with Chang selected in a same day replacement vote).
The recall was launched over a gas tax and the Republicans push to deprive Democrats of a 2/3rds supermajority in the Senate. The Democrats quickly recaptured the supermajority in the fall elections.