Eric Bauman is a D Party insider from the Land of LA; Kimberly Ellis is somewhat of an insider, but really hasn't "paid her dues". Just looking at their relative experiences and ignoring the internecine stuff, He's got the knowledge and experience, where she would have been out of her depth.
Factoring back in some of the real-world "stuff", she's black, and he's white. Outside of politics, skills, knowledge, and experience should be what matters, but skin color matters in the D Party.
In CA, D Party insider vs. Bernie-ite is mundane lunatic vs. crazed lunatic. The Ds rule CA and are destroying it; the difference between these two is how swiftly CA crashes into some sort of wall and how much it burns.
Bauman is from the Great and Glorious Land of LA; Ellis is from Richmond, a grungy northeast SF Bay Area city of ~110K. Unlike the USC, CA's constitution has no provision that could hinder a populous city and county like Los Angeles from lording it over and oppressing the rest of the state (often with the help of San Jose and San Francisco, the 3rd and 4th largest cities in the state). Given that reality, it's surprising Ellis came close.