If ever California truly left it would not be only California going. It would be the most prosperous and liberal east and west coast states all leaving at the same time. Under such a scenario the mouth breathers would only be left with the center and deep south, and in any war that resulted they would lose. Military might is dependent on technological and economic might, and the east and west coasts way outclass the rest of the US in terms of technological and economic might.
It would Partysaurus Rex and his fellow travellers who would be doing the dying. Not Californians.