By winning a LOT more Hispanic votes. California isn't some DuPage County, IL that voted Republican for a long time and then a few Republicans defecting + a tad more diversity flipped it. California has fundamentally changed, and does not resemble the state that voted for Bush 41 in 1988 (and not by much!). This is California's Non-Hispanic White percent by year:
1970: 89.0%
1980: 66.6%
1990: 57.2%
2000: 46.7%
2010: 40.1%
It's gone for quite a while.
Winning far more Hispanic votes still wouldn't do it. The majority of non-Hispanic whites now vote Democratic.
