Not true. Unless, by "save" you mean to turn more blue.
While "Whites" are nearly split (D) / (R), the "Latinos" are by far more (D) than anything else.
Fewer "Whites" as a percentage over the recent years has meant moving away from Reagan, and towards Newsom.
https://www.ppic.org/publication/race-and-voting-in-california/
As an aside, its ironic that regarding historical political party strength, Texas has elected more Democrats at both the state and national level, than California has.
Demographic changes in the last several decades have indeed had their affect. CA is a harbinger for what's to come in Texas and elsewhere as legal and mostly illegal immigration change the country.