They need to consider a compromise. Allow only the mentally-ill, deep-blue, RAT portion of the state to secede.
The State of Jefferson would come of this. Much as the Northwest counties of Virginia appealed to Congress to recognize the region as the new state of West Virginia once Virginia seceded from the Union. The new nation of California would lose it’s entire inland empire and the federal government will treat North Island and Pendleton the way we did Guantanamo.