CA in 1976 was the last real horrah though for the "moderate" leading the ticket. Although Bush 41 was somewhat moderate, he won CA because of Reagan. Without Reagan, the pacific rim would have been solidly blue. Ford also lost a ton of inner counties, but narrowed his losses in LA and killed Carter in Orange County and southern CA to carry the state.
The influx of illegals turned CA blue and (as I'm moving to LA within a year or two), that is a major political issue. If the illegals get booted, the state would suddenly become very competitive again.
There is so much wrong here.
1. There was no problem of "being too conservative" for the GOP in 1988. Bush's numbers in New York for instance and CT, NJ, and ILL should prove that. CA had become more and more Dem starting after 1976. Reagan probably slowed the decline down but in 1986 LA county went from have mostly Republican officials to Dems.
Now since the early 1990's there has been declines in the Bay area and LA suburbs that can be attibuterd to the prominence of Social conservatism.
In 1996, naturalization of new citizens did double then declie by 50% the next year. One could argue that the wave of new citizens in CA helped push it more Dem.
Illegal alien voting can explain a small loss in a marginal district. But widespread illegal alien voting doesn't not account for more then .002% of CA's 20% Dem advantage in 2008.