Um, no, the voters of California cannot decide to break their state into any number of states. The US Constitution requires the state legislature to the US Congress to make such decisions. See Article IV, Section 3 if the US Constitution: “New States may be admitted by the Congress into this Union; but no new State shall be formed or erected within the jurisdiction of any other State; nor any State be formed by the junction of any two States, without the consent of the Legislatures of the States concerned as well as the Congress.:
This referendum is NOT THE END but the START of a process.
From the article:
“CAL3 can be passed by a simple majority in November, if it is put on the ballot. If it passes, the state legislature will have to approve the request to divide the state and the governor will have to sign the bill. After that, the request must be approved by the U.S. Congress.”