California economy is on the order of France and UK.
Country like Israel, with much less people and smaller economy, manages to desalinate and recycle its water in the middle of desert, surrounded by hostile neighbors.
Most likely the US could halt 1/2 of its food production and still have plenty of food. We have no shortage of arable land, we have a greater shortage of people actually wanting to be farmers/ranchers :(
Not in terms of calories.
The rest of the US could live just fine without out-of-season artichokes or whatever.
Water is rather more important. You can live a long time on a plain diet (especially if you have vitamins available). Without the water, things in California would get very, very ugly, very, very quickly. ]
Also: what are you planning to do if (or maybe "when" would be better) Mexico decides that it wants to take back its former territory (i.e., all of California)?
I think an independent California would have a good relationship with Mexico. Though I'm interested in why you think we wouldn't.
There's nothing standing in the way of that now. Colorado just had the opportunity to vote in a single-payer healthcare system.
You're saying "what if a government spent more than they had", but that's hardly unique to a seceded California. I don't see how it's at all relevant.
California is not a net payer. According to wikipedia (and I realize these are from two different years, but they're the easiest numbers to find), California pays $7,690.66[1] in taxes on a per capita basis and receives $8,967[2] in federal spending on a per capita basis.
1. https://en.wikipedia.org/wiki/Federal_tax_revenue_by_state#F... 2. https://en.wikipedia.org/wiki/Federal_taxation_and_spending_...
This map / story from 2014 says otherwise. http://www.theatlantic.com/business/archive/2014/05/which-st...
1. https://en.wikipedia.org/wiki/Federal_tax_revenue_by_state#F...
2. https://en.wikipedia.org/wiki/Federal_taxation_and_spending_...