What would need to happen for California to trend to the right?

[S019]

The GOP creates a TIME MACHINE to turn the clock back to 2000, and decides to pursue policies that won't alienate suburbanites

[Sestak]

Eventually they'll cap out and then it may trend back R a little at one point.

[sterk001]

Well I think it depends on if the GOP can appeal to the hispanic population, which comprises a huge part of the electorate. Several of my hispanic peers (18-25) are pretty socially conservative, and have been trending Republican for several years now, although they like to identify as Democrats due to the CA GOP having a negative association. I can tell you the GOP can definitely make inroads with Cubans and Puerto Ricans in California (although they represent less than the ethnic Mexican-American electorate does), as I know a few of both that have trended R for some time now. I'm not sure about the ethnic Mexican-American population though. I have to apologize for my small sample set, but I've noticed that Puerto Ricans and Cubans here lean conservative, especially on social issues. It's a little odd that Puerto Ricans here do so, because in other urbanized states they're more liberal, but I actually know a couple that are ultra conservative on issues like immigration and social issues.

But to answer your question, I think it requires a combination of appealing to the hispanic electorate, boosting your standing among Asians (which is doable for the GOP sometime post Trump), keeping your margins among white rural and suburban voters who vote GOP (which is the hard part to mix this with the two above), and some kind of socially moderate/fiscally moderate candidate for statewide races.