"I'm supporting a Democrat in the runoff and look forward to the voters making that decision very shortly..." Newsom said. "... There are a lot of outstanding candidates with extraordinary records. I could name seven of them, although I think there were nine."
More than a week ago, Eric Swalwell dropped out of the race due to sexual assault allegations. The Democrat also resigned from his seat in Congress.
Before the allegations, he was widely considered the gubernatorial front-runner for the Democrats.
On Monday, Democratic candidate Betty Yee suspended her campaign for California governor after tracking near the bottom of polls.
Democratic party leadership had previously called on candidates polling in the single digits to drop out of the race.
The latest poll from Inside California Politics and Emerson College Polling now shows Xavier Becerra with a massive jump among Democrats.
Former Fox News host Steve Hilton continues to lead on the Republican side.