Well, they VOTE like homosexuals and other assorted progressive undesirables, hence the sanctuary city designation.
You are correct on that point. But things can, and will change as the demographics change. The asian population grew, and got a Chinese mayor elected (instead of the gay candidates or hispanic candidates). The far-left liberals still dominate on the Board of Supervisors and other power positions, so the Chinese mayor goes along with them. Now, with the influx of straight white tech workers, many of whom are married parents with children, the voting should trend more conservative. People want their kids to be safe. SF was a republican city for most of the 20th century until the mid-1960s and an influx of outsiders from the east coast ruined it (same goes for California in general). Hopefully it can shift back to saner politics.