Former Health and Human Services Secretary Xavier Becerra and billionaire Tom Steyer are vying for front-runner status in the California governor's primary race after former Rep. Eric Swalwell (D) dropped out due to sexual assault allegations. The candidates were among four Democrats and two Republicans in a debate. Steyer won the backing of the California Teachers Association and Betty Yee, who suspended her bid last week. Meanwhile, Democratic leadership is warning that the crowded field could pose a low but "real" risk of two Republicans gaining top two spots in the June 2 primary. The latest Emerson College Polling/Inside California Politics survey showed Republican Steve Hilton leading the field with 17 percent, followed by rival GOP contender Chad Bianco and Steyer, tied at 14 percent each.