Officials announce proposal that would establish California as separate nation

Gotta pass the state referendum first... historically they don't

US Supreme court has ruled that states cannot secede from the union:
Texas v. White

the court further held that the Constitution did not permit states to unilaterally secede from the United States, and that the ordinances of secession, and all the acts of the legislatures within seceding states intended to give effect to such ordinances, were "absolutely null"

Chase, [Chief Justice], ruled in favor of Texas on the ground that the Confederate state government in Texas had no legal existence on the basis that the secession of Texas from the United States was illegal. The critical finding underpinning the ruling that Texas could not secede from the United States was that, following its admission to the United States in 1845, Texas had become part of "an indestructible Union, composed of indestructible states." In practical terms, this meant that Texas has never seceded from the United States

It'll never happen, but if it did, Dems would never win another election here.