No. Why let immigrants, illegals and drug addled hippies make that decision?
A better idea . . .just kick them out to somewhere wher they can all sing Kumbaya together and keep The Formerly Greatest State of California in the Union
Make California Great Again
DJT, I think, would see it differently, just as Abe Lincoln did in ‘60.
There is no union under your scenario. Many, if not most, states were CREATED by the fedgov. Once the constitution was ratified the idea of a conditional ratification was squelched (see Madison and Hamilton’s correspondence during the NY ratification convention.) Once in the union, always in the union.
Attempts to secede using force are insurrections. If Congress voted to allow secession of a state presumably that would be legal whatever its horrendous practicalities.
Never. Because it surrenders the principle that they have the right to flood any zone they desire with sufficient foreigners, they can take anywhere like that.