California would lead the charge, if any state were to secede. Liberal Land. California has the largest economy of any state, they are prosperous.

However if they seceded they wouldn't last five years. Starry eyed idealists like Lanny Davis would open the border to any Wetback, and give them welfare and full medical care. The word would get out, in Guatemala, and El Salvador, and Mexico.
The population of California would double in five years with Wetback freeloaders, and California would collapse.