I don’t see how this plays out; Hillary needs the first ballot to fail at the convention so she can ride in on the Superdelegates and get the nomination. You got Steyer and Bloomberg carpetbombing the airwaves with ads, California starts voting on Monday when vote by mail ballots are delivered, and Bernie’s presently got a good path to win on the first ballot.
Mind you, 45% of California’s voting will be completed by Monday 2/24, so they’ve got just days to sink Bernie enough to make a contested convention.
Truly a sobering thought - that anyone would regard Bernie seriously as a viable candidate for POTUS (much less the hildebeast)...