The GOP put itself out of power in CA by pursuing a series of explicitly racist policies in a white-plurality state, and then later settling on total political obstruction as its backup plan (in the short term this was effective at preventing the state government from addressing a wide range of serious problems). My former GOP state rep in SoCal used to send out mailers proudly proclaiming that he had voted ‘no’ on 100% of legislation, with some race baiting mixed in as seasoning. Considering that a couple decades of this led to the Democrats winning all of the statewide offices and supermajorities in both houses of the legislature, perhaps it wasn’t the best long-term strategy.

But the state remains a very conservative place overall, just like the rest of the USA. There’s a broad swath of the public who distrust the government, are opposed to taxes of any kind, and so on. Even in 2020, 34% of voters picked Trump, even though his rhetoric has included badmouthing CA as a cornerstone. And many CA Democrats are pretty conservative by the standards of most other developed countries, and would most naturally fit in a centrist or center-right party.