If California did secede from the Union, the Democrats would never again control the Federal government, and Trump-style governments would rule forever, especially if New York also secedes: it is just as crazy left-wing as California, after all. That would take almost all the dark Blue out of the Map:
The dark blue areas are where Clinton got 60% or more of the public vote: without California’s crazy voters the Democrat party could never win an election. This is why the recent discriminatory laws against Red States are not a precursor to secession: they are more like a childish tantrum, or at best a protest. The Democrats will never let California secede: they need California for their very survival.