It is unlikely that the progressive majority on the Board of Supervisors is going to go for this measure, so the supporters of this ban are already starting to gather or lay the groundwork for gathering voter's signatures.
On a 6-1 vote, Planning Commission decided not to take a position at all on this controversy.
Newsom's proposed law would be city-wide, but the Haight-Ashbury neighborhood is at the epicenter.
The area is known for street people. They are even a tourist attraction, but in recent months complaints have escalated about threatening and violent behavior.
"We need the law in place for bullies on Haight Street. I've been punched in the face for not giving someone money," resident Andrew Van-Wart said.
Newsom's measure would make it illegal from 7 a.m. until 11 p.m. to sit or lie on a public sidewalk, even on a blanket, a chair or a stool.
A young woman who wished to remain anonymous said what she's doing is freedom of expression.
"We have the right to sit down and rest if it feels good. I think the mayor himself probably sits down on the sidewalk once in a while," she said.
Opponents of the ban staged sit-ins around the city this past weekend, saying it doesn't reflect San Francisco values. The Lawyer's Committee for Civil Rights is concerned about selective enforcement.
"Someone sitting on the sidewalk in business attire will likely not be the target of enforcement -- rather someone who looks downtrodden, poor, perhaps homeless, a day laborer sitting on a sidewalk," Laura Hurtado from the Lawyer's Committee said.
But police say that's not the purpose of the law.
"Our position is this legislation does not target individuals, it targets behavior. A lot of people out there in the community think it targets people, and it doesn't," SFPD Assistant Chief Kevin Cashman said.
Newsom modeled his measure after a Seattle law which passed in 1993 and has survived a legal challenge.
The San Francisco proposal still faces a number of hurdles, including the Board of Supervisors. In the end, the ban could wind up before voters.
A Chamber of Commerce survey found 71 percent of those polled support it and it's the topic of lively debate even among street people in the Haight.
Later this month, the Small Business Commission is expected to weigh in, and then it will go to the Board of Supervisors.
Berkeley, Palo Alto and Santa Cruz are some of the other Bay Area cities that have some form of sit and lie ordinances in effect.