While this assertion sounds plausible, keep in mind that California has been losing moderate to conservative population for years.
While their population continues to rise some, it is mostly a function of massive legal and illegal immigration, mostly from poor countries and these people have a far higher fertility rate than the Californians of two or three decades ago.
Bottom line is the "takers" are coming and they are multiplying after they get here.
2.5 million folks die every year. High percentage of them are old white people who vote Republican. Being replaced by non-whites that vote Dem 70% plus.