Reflecting the timeworn tactic of aggrieved parents of little children everywhere, some San Francisco Democrats are calling on BART board Director James Fang to say he's sorry. And to never, ever, do it again. What's the behavior in question? No, not throwing his food or hitting his little sister. Fang - the only elected Republican in all of San Francisco - got a somewhat surprising boost by the Democratic County Central Committee last month when it voted "no endorsement" in his race to keep his seat and fend off his challenger, Democrat Nick Josefowitz.