There is a US Constitution question that they will run into:
Article IV, Section 1: New States may be admitted by the Congress into this Union; but no new States shall be formed or erected within the Jurisdiction of any other State; nor any State be formed by the Junction of two or more States, or parts of States, without the Consent of the Legislatures of the States concerned as well as of the Congress.
In my view, the people themselves can act as their own legislature and make law, so I have no problem with the ballot question. The courts however, may not agree and may require the consent of the CA legislature.
And then they’d have to get permission from the Congress.
Lol. The founders were brilliant!
It's not an issue. The proposition is not the binding act.