Mayor Gavin Newsom had been reluctant to push a sit/lie ordinance, telling The Chronicle editorial board earlier this month it was just too divisive to support.

Then he took his 5 1/2-month-old daughter for a stroll on Haight Street one Saturday morning.

"As God is my witness, there's a guy on the sidewalk smoking crack," Newsom said.

Suddenly, the issue became more personal. On Friday, Newsom revealed that he will introduce a sit/lie ordinance to the Board of Supervisors next week.

Get ready for predictions of the end of the world as we know it. The ordinance will give police officers the ability to order abusive sidewalk squatters to move away from homes and stores. But homeless advocates are likely to paint it as an effort to criminalize homelessness and round up and arrest the poor and disadvantaged.

They've demonized laws like this with success before, which was one reason Newsom didn't want to "get caught up in the sideshow," as he said at the ed-board meeting. But he is convinced he can make the case that this is about inappropriate behavior. "I cannot impress on you more, this is not a homeless issue," Newsom said. "I am living here, I am taking these walks with my family, and I'm amazed that these people have put up with this for decades."

While we are at it, let's give credit to the neighbors and merchants of the Haight. For all the talk about how nothing ever gets done in the city - either important issues are talked to death or they are watered down to the point of being worthless - the residents of Newsom's new neighborhood put on a clinic for getting things done.

With the help of community organizations like the Haight Ashbury Improvement Association, the residents have pushed the sit/lie debate. And this week they followed that up with an innovative plan to subsidize the cost of installing video cameras at local stores. Instead of the useless and over-priced crime cameras the city has installed; the private $300 video cameras will give police clear, useful images.

All of that was done with effective grassroots organizing. Kent Uyehara, merchant chair for the association, says efforts to organize locals used to be met with indifference.

"They'd say, 'I've been here 27 years. We tried that before and it didn't work. Why would you think it would work now?' " Uyehara says.

There are several reasons. For starters, new Police Chief George Gascón has proved to be an effective advocate for new ideas. He got behind the sit/lie ordinance, allowing the Haight's police captain, Teresa Barrett, to recommend the idea at neighborhood meetings.

When critics complained that current laws could accomplish the same goals as sit/lie, Barrett pointed out that San Francisco police cannot legally require people who are blocking sidewalks to move unless they have a formal complaint from a citizen. That leaves the person making the complaint open to retaliation.

With the police backing the issue, the neighborhood rallied.

"In the last three weeks, I have seen more merchants wanting to get involved than in the 15 years I have been here," Uyehara said.

Supervisor Ross Mirkarimi, who represents the area, has waffled on the issue. But he began to hear a steady drumbeat of support for sit/lie. Mirkarimi is holding a hearing on the matter at Monday's 10 a.m. Public Safety Committee. Expect some lively debate, especially now that the mayor has taken a stand.

Frankly, the ordinance is probably a longshot to pass at the board and is likely to end up on the November ballot.

So won't Newsom have to stay in the mayor's office to shepherd the legislation through? Surely he won't want to leave for the lieutenant governor's office knowing that he'd have to turn his sit/lie ordinance over to an interim mayor elected by the Board of Supervisors.

"Oh I'm sure Mayor (Aaron) Peskin can handle it," Newsom said.

He was joking.

I think.