San Francisco politicians, eager to showcase their democratic credentials in their liberty-loving city, traditionally have not shied from taking stances on human rights, checking in on everything from apartheid in South Africa to Burma’s military junta. [...] on Wednesday, as tens of thousands of peaceful democracy demonstrators who had already been tear-gassed marched in Hong Kong, Mayor Ed Lee was on his City Hall balcony hoisting the flag of the target of those protests — the autocratic government of China. The occasion was China’s National Day, the 65th anniversary of the founding of the communist state, and the flag ceremony occurred a few hours before about 150 pro-democracy demonstrators protested in front of the Hong Kong Economic Trade Office in San Francisco. Much of the rest of the world, however, has been watching the scenes of protesters using umbrellas to protect themselves from tear gas. Lee, who has taken multiple state visits to China and courted Chinese companies to try to persuade them to set up offices in San Francisco and invest here, would not take a position on the protests but called for “discussions.”