Or possibly "Central California" due to Baja. Presumably the state with capitol in Sacramento would be the successor to the current California.
The line of division would be 35° 47′ 28″ North latitude - the northern border of San Luis Obispo, Kern, and San Bernardino counties.
It seems inevitable that in 50 years, either California will be multiple states in the United States, or it will be an independent country. It is in the interest of the United States that the first scenario occur.
This will also be a step towards decreasing the representational inequities of the United States Senate.