This post from Mathew Yglesias is very interesting. I've never seen a take on California's budget problems that focused on population before, but this makes sense. California couldn't keep growing at the rate it grew during the Fifties and Sixties. If it had, then much of what we love about California would have gone away. If California's approach to government services was based on the budgetary advantages of a rapidly growing population, then that level of government services may not be sustainable if we now assume that California is built-out.
The Decline of California