How you determine what is "Northern" and what is "Southern" ?
On a county map of California, there's a nice line through the state.
The one Between San Bernardino-Kern-San Luis and Inyo-Tulare-Kings-Monterey ?
Yes, although Kern is a little debatable. You could put it in NorCal if you wanted to keep the Central Valley together, although there definitely are crazy people who commute from Bakersfield to LA.
There are two possible definitions, one which divides the state exactly along that line and another that puts Kern, San Luis Obispo and Santa Barbara Counties in NorCal. The latter is slightly more geographically reasonable, keeping the coast and Central Valley communities together, and also making the two states more even in population, but the former looks better on a map.
You know nothing about CA. 
I don't see what's so wrong with what he said. Kern County is definitely more a part of the central valley than Socal and it would make sense to keep the valley together. I disagree with him about SLO and SB though. Although they are coastal counties, they identify much more with LA than they do with any other area and thus should be in any Socal state, especially SB.
He suggested Kern being placed in Northern CA. Fresno is debatable, but Kern is definitely Southern. A Valley state, sure it could include Kern, but not a Northern-Southern split.
I think he had a valid point that the valley should be kept together. In reality it doesn't matter that much. In my opinion Kern should be part of Socal and so should Tulare and Kings.
If Tulare and Kern are going to So. Cal, it'd be wise to add Fresno, Mariposa, Madera, San Benito, Inyo, Santa Barbara, Ventura, San Luis Obispo.
