One would think that the Republican Party would learn from history and its own mistakes.
A generation ago, California was Republican, and then passed legislation (Proposition 187) to crack down on illegal immigration, denying any health, education, and other benefits to such people, heavily Hispanic, but also Asian, and since then, the Republican Party has died out in much of California, and has not win a state wide race in the past decade. The ballot initiative was declared unconstitutional in 1999, and is no longer enforced since then.
The likelihood is that California will have many election contests in 2018 and beyond without Republicans competing, as the Golden State has a system that allows the top two candidates in votes in primaries, even if of same party, to be on the ballot in November.
So except for a minority of House of Representatives seats in the rural interior and other limited areas of California, and a minority of state legislative seats, California has become extremely dominated by Democrats in state wide races, and in the vast majority of legislative seats, both state and national,
Former Republican Governor Pete Wilson is the culprit in this nativist approach, which has led to this disaster.
If the GOP does not watch itself, this could happen in other states, and destroy the Republican future, and Donald Trump could become the national example of Pete Wilson.
The fear instilled in California has backfired totally on the reputation of the Republican Party.