Here is a concise original summary based on the information published by the source. Bernie Sanders makes a late push for California billionaire tax PoliticoGoogle's Sergey Brin has now donated more than $100 million to oppose California's billionaire tax FortuneTop Democrats battle over California's proposed billionaire tax ABC News - Breaking News, Latest News and VideosCalifornia poll: Voters back a billionaire tax, but the proposal falls short of majority support NBC NewsBernie Sanders rallies in S.F. for ‘the most important ballot initiative in the country’ San Francisco Chronicle For the full context and any later updates, use the original source link.