It's possible. One option is shifting coalitions to put the Hispanic vote more heavily within the Republican column.
I’ve said this before, but even if CA Hispanics start voting like FL/TX Hispanics, white liberals who are still in the state and particularly in the Bay Area will mean that it still ain’t gonna be within 15 for the time being.
CA going red would require the population of the Bay Area in particular to change their way of voting drastically, and I don’t know how that happens any time soon. I can absolutely see SoCal trending/swinging red (including LA) and most of the non-Bay Area parts swinging right too, but the Bay itself swinging right would require a massive population change or a re-alignment of sorts.