What is missing from the equation is the dependency that California has upon the rest of the US.

Assume for a minute that California suddenly became a seperate country.

First, water. If you think that Arizona, Nevada and Oregon are going to cede water to another nation you'd best think again. And there are no Great Lakes, such as the US shares with Canada, to create treaties about.

Second, transportation. California would have seaports and airports, but no other way in place to move goods out of the country since there would be no treaties in place allowing the use of the US road system. And you might as well not have the goods if you can't bring them to market.

Third, the Interstate Commerce clause of the US Constitution would no longer be effective for California. What industries would be left (and I think they'd bail out long before California declared nationhood) would not be in a position to market effectively to anyplace outside California, or at least for some time to come.

I suspect that if California became a seperate nation it would sink way, way down the list.