CA’s huge electoral chunk went to the GOP nominee for Prez in every election from ‘68 to ‘88. And that was that. The cause was a combo of demographic change and increasingly liberal (brainwashed) white population.
See post 4, the white Californians didn’t change much, it was the immigration.
You have to remember that while illegals aren’t voters, they are bodies. The democrat plan began as a way to increase democrat House representation. By increasing the number of illegals, those numbers would reflect in the decennial census and additional House members would result. So without citizenship, the humans alone helped to alter the political balance.