It might be interesting at this bloody moment in SF to recount an August column by C.W. Nevius in the San Francisco Chronicle:
In July 2004, Mayor Gavin Newsom was confronted by a morning radio show caller who complained about the homicide rate. Newsom's flip reply was that if homicide rates didn't drop in a year, the caller could "begin a campaign to recall me. And you know what? I may be right there as a co-signer of that effort."
When it comes to wisecracks the mayor wishes he never said, that has to be at the top of the list.