He is urging voters to approve the so-called "sit-lie" measure.
Prop L would ban sitting or lying down on city sidewalks between 7 a.m. and 11 p.m.
People who oppose Prop L did their own campaigning, by handing out flyers on Haight Street Saturday. They say it would result in unfair treatment of homeless people, and day laborers.
They say there are already more than a half a dozen existing laws that police could enforce through more foot patrols.