One in three Californians are brain dead.
Democrats would lose an easy fifty-five electoral votes.
Democrats would lose two of the worst Senators in the U.S. Senate.
Democrats would lose a bunch of House seats.
The United States would lose millions of illegal aliens.
The United States would become nearly 70% white again overnight.
It'll never happen, but I'd love to see California leave. If by some miracle they get 50%+1 to vote for this, President Trump should pull a reverse Lincoln and say he supports their right to self-determination.
I suspect though, most of the ultimately small percentage of pro-secession votes this referendum will receive will be ironic, i.e., voting for it only because they know it will not pass.