There isn't much room for California to raise income or sales taxes, which means property taxes are next. A popular referendum will modify prop 13 and the State will inch up property taxes little by little, buoyed by one widely-publicized, world-is-ending, save-the-children 'crisis' after another (first health care, then pensions, and after that, your guess is as good as mine). In reply to your question: they will be busy taxing everybody, not just foreigners.
To discourage foreigners buying property? A giant reason for home prices in California being so high are all the regulations restricting zoning, building codes, etc. Real changes would never really happen to "increasing affordable" homes really, as no rational homeowner wants to see their home values decrease.<p>On the side for demand, it's clear California's coast is the "chic" place for people to be. Not to mention relatively safe investment spot to stash foreign money away.
This question is most likely a follow-up to the recent
discussion <i>Vancouver house prices are falling</i>:<p><a href="https://news.ycombinator.com/item?id=13569550" rel="nofollow">https://news.ycombinator.com/item?id=13569550</a>