What is the Political Geography of California?

[MarkD]

That's all i wanted to say on this subject. And it portends big problems in the future. After all -  talks about splitting California into up to 6 states arose mostly because of existing political situation, and they may be a harbringers of what will come...

An initiative to divide California into 3 states has been submitted for review by the Attorney General. It is much simpler than the 6 California proposal, and would simply give California's legislative consent to be divided into three states (when Kentucky, Maine, and West Virginia became states, Virginia, Massachusetts, and Virginia legislatures gave consent).

Virginia had given consent for the formation of Kentucky while the Constitution was being ratified. The Continental Congress decided not to act while the Constitution was pending. When Maine split off, a very large share of the population was in Maine, and one might have even conceived that a majority of the population would be in Maine. Consent for formation of West Virginia was given by the remnant of the legislature that was meeting in Wheeling. After West Virginia became a state, the Virginia legislature was dormant.

The three proposed states are:

California: Los Angeles to Monterey + San Benito.

Northern California: Everything else north of Merced/Mariposa, except Mono.

Southern California: Everything else south of Fresno/Madera, including Mono.

In such case "California" and "Northern California" will surely be Democratic, "Southern California" - probably swing...

"California" -- six counties, 2010 population 11,805,781; voted for Clinton 69% to 25% for Trump.
"Northern California" -- 40 counties, 2010 population 12,392,396; voted for Clinton 65% to 28% for Trump.
"Southern California" -- 12 counties; 2010 population 13,055,779; voted for Clinton 51.57% to 41.86% for Trump.

It's not at all clear how the current 53 seats in the House would be divided up.