The big boost came in the 1960s with the defense industry. That and a huge government investment in education. The fine public school systems, now enfeebled by this debt, have long been the main selling point for real estate agents. Without the state plunking UC Irvine down in the middle of nowhere, the cows of Irvine Ranch would still be listening to the asparagus grow. What the county has to come to grips with is that the free lunch catered by federal and state governments is over.
Local taxes have to be raised or government services cut.
The majority in the county has consistently refused to do either, which is why elected officials were forced into financial shenanigans to cover the shortfall. It won't work anymore. The true keepers of the conservative faith on Wall Street have served notice.