West California would still be one of the most populous states in the union, coming in just behind Ohio in 7th place and South California would be nipping on its heels. Silicon Valley would be ranked near Tennessee. As crazy as this proposal sounds, it's probably less crazy than having almost 40 million people be represented by just 2 senators when Wyoming has the same number of senators for barely half a million people.
This was purposely the design of the Senate. This complaint should be more applied to the House, where we stopped increasing the number of reps as population grew
1790: 12x (Virginia : Delaware)
1850: 36x (New York : Florida)
1900: 173x (New York : Nevada)
1950: 93x (New York : Nevada)
2000: 69x (California : Wyoming)
2020: 68x (California : Wyoming)
It's a far cry from Wyoming being ~1% the population of California (~.17% of the US pop), but I think they and the first few generations of american politicians were reasonably aware of the potential spread.
Also have you ever been to Marin? A lot of people there are fairly "conservative".