As social/govt. services dry up, professionals will leave in droves as who wants to pay 10-13% state taxes when alot of other states offer way better tax rates with better quality of life. Think the homeless situation is bad now with tent cities everywhere, wait until the yearly $15B that CA spends on homeless disappears.
I predict a hyper exodus as the state suffers an economic collapse that will take most likely a decade or two to recover from. Lets also not forget that the 20th century was the wettest in the past 2000 years in CA and the 21st century will be very dry(which is normal for this state), so CA's agro economy will rapidly shrink, and water loss will force population out.
Oh and by the way I am a 4th gen. CA resident so its tough for me to acknowledge these facts.