San Diego with a 70 mile coast line and a population over 3 million does not have in common much with the small inland towns in the mid and north.
A non starter.
Cut the state in thirds from west to east.
There would be downsides. I can't see how one could reasonably separate San Bernardino from LA. Sorry Salinas; it's gotta suck to be stuck with Santa Cruz.
Inasmuch as it would be great for California conservatives to have a state again, the net result would be plus 2 liberal senators. I'm afraid the inland state would suffer the same consequences as the flyover states, haltered by the Federal boot on their necks. At least they'd get to flush Sacramento!
DOA of course, but I sort-of liked my section being cut off from some of the others. Politically though, SLO County has as much or more in common with Kern than it does with either liberal democRAT infested Monterey, and (particularly) Santa Barbara Counties. That was until the last election cycle...in which SLO County went 'rat in the presidential election, same as most of the rest of the Coast.
I'd bet that city-by-city Paso Robles might have remained Republican. Most of the out-lying rural folks county-wide, do not vote 'rat, which is why the County has been [Lois] Capps-o-mandered, splitting the city of SLO off from much of the rest of the County, lumping it in with her home turf of Santa Barbara, leaving much of the balance of the County grouped with Kern for U.S. Representative Districts.
Smug San Diego County voted for Obama. They can fall into the sea for all I care if they didn’t have the bases.