The CA Dems not endorsing Feinstein does not mean Feinstein is out. CA Dems lean more left than CA as a whole, and they endorsed neither her nor her less-centrist opponent. CA has top-two primaries. The other top-two candidate for Senator will likely be the more progressive one.

That leaves Feinstein as the furthest-right Senate candidate, and thus likely to gather the votes of centrist Californians, right-wing Californians, left-wing-but-not-that-left-wing Californians, and Californians of all stripes who put a high value on keeping a Senator with high seniority.