The First Estate of Silicon Valley (here, including San Francisco) are the highly influential angels, VCs, and corporate executives who can force acquisitions.

That would mean the Zeroth Estate are the landlords. Remember, Google proposed to Mountain View to build their own damn neighborhoods of townhouses and apartments for housing their own employees. They got denied. The city council somehow felt that the current situation was better than letting a company, God help them, actually get some housing built for all those employees they hire.