The question is, at what point is continued membership in the US a bigger problem than splitting from it would be?
California is large enough and prosperous enough that they could definitely make it as an independent nation, but the transition would be extremely difficult.
But on the plus side, there aren’t legions of “lone wolf” nut jobs just aching to murder you in the name of Dear Leader, who Dear Leader is only too happy to encourage while taking away whatever protections you have from them.
So, you know, give and take.