A controversial new housing law had its day in court Thursday when it went before the Planning Commission for seven hours of comments and deliberation. Minutes earlier, a press conference on the steps of city hall was held in opposition.

“On its face, [this program] promises to increase affordable housing,” said Supervisor David Campos, flanked by more than 70 people crowding city hall steps. “But if you actually look at the specifics of this proposal, it will incentivize not affordable housing, but the displacement of thousands of San Franciscans.”

The housing measure — known as the affordable housing density bonus program — would give developers two extra stories in exchange for building 30 percent affordable housing on-site. It has been bitterly debated for months, some calling it “Redevelopment 2.0” and others saying it is a common sense means of extracting more affordable housing from private developers.

Regardless, the commission punted the proposal until February 25 in a 4-2 vote, an acknowledgement that the law as-is leaves too many questions unanswered.

But testimony during the hearing — mostly against the proposal, with some in favor — once again showcased the tension that accompany any proposed housing fix in San Francisco.

“This is ethnic cleansing,” said Calvin Welch, a longtime housing activist. Because the program is most prominent in traditionally ethnic neighborhoods like the Western Addition and Bayview, Welch said it should allow residents of those neighborhoods to take advantage of the affordable housing on-site.

But the incomes of black, Latino, and Asian populations are much lower than for their white counterparts, Welch said, and the law rests on median income city-wide. It would effectively prevent minority populations from entering that housing, Welch said, clearing out those neighborhoods.

John Rahaim, the director of the Planning Department, struck back against that characterization of his staff’s efforts.

“It’s offensive,” Rahaim said to Welch. “We’re trying to have a reasonable conversation here.”

“It is offensive to me that the city of San Francisco would propose a program that is higher than the median income in 60 percent of the neighborhoods you’re going to do it in,” Welch retorted.

It was the only such exchange of the day, but talk of wholesale displacement — and comparisons to redevelopment from the 1950s to 70s — was common Thursday. Opponents of the program were particularly concerned about the destruction of rent-controlled units, which was initially allowed under the program.

But in response, Supervisor London Breed drafted an amendment that would explicitly exclude rent-controlled units from the program.

“President Breed’s intent is to amend the legislation such that there is a permanent prohibition on the destruction of rent controlled units,” said Connor Johnston, Breed’s aide, at the commission hearing.

The news was well-received by those in the hearing room — which was filled to capacity, with dozens relegated to an overflow room down the hall — but only addressed one of myriad concerns that opponents say warrants the scrapping and re-imagining of the program.

“Our goal is to kill it and go back to the drawing board,” said Fred Sherburn-Zimmer, the executive director of the Housing Rights Committee, before the hearing.

Housing developers are currently required to make 12 percent of their on-site units affordable to those making about $39,000 a year for one person. They can also build 20 percent affordable off-site or pay an in-lieu fee.

The new program requires an additional 18 percent. But those extra units only have to be affordable to individuals making some $86,000 to $100,000 a year. That threshold, which allows developers to charge more in rent, was a rallying call for those who said it amounted to subsidies for market-rate tenants.

“You’re redefining affordable housing as market-rate,” said Deepa Varma, the new executive director of the San Francisco Tenants Union. “Who benefits from that? Only developers.”

A flurry of other concerns were raised on Thursday. Many lambasted the lack of community input during the program’s creation, saying the Planning Department only reached out to community groups once the law had been drafted — a perennial concern in the creation of housing measures.

“They’ve talked about this plan for two years,” said Marie Sorenson of the merchants association Calle 24. “They haven’t met with anyone in the Mission.”

“I live in the Mission District, I have never heard about this,” said another speaker. “I heard about it by accident through a posting on Facebook.”

The Mission District featured strongly in opposition to the program, though of the eligible parcels city-wide, just 1 percent of them are in the neighborhood — mostly on South Van Ness and Guerrero.

“The majority of the Mission District does not apply here,” clarified Gil Kelley from the Planning Department.

Still, some were concerned about commercial displacement. Since single-story buildings with ground-floor businesses are potential sites for new housing construction, meaning the displacement of a commercial tenant.

“If they were to be displaced, they would lose their entire investment,” said Erick Arguello of Calle 24. Businesses cannot easily survive in another location during the time it takes to rebuild, Arguello said, resulting in permanent displacement and possible closure.

Others said the technical details of the ordinance needed reworking. Fernando Martí, the co-director of the Council of Community Housing Organizations, said he wants “a much different, much more nuanced approach” that re-evaluates the size of units, their affordability, the relocation of displaced businesses, and other details.

Though the law’s opponents outnumbered its supporters, the latter — wearing stickers that read “Build middle class homes” — said there was a dire need to extract affordable housing from private developers and that nit-picking over technicalities did not merit stopping the program altogether.

“I feel like these concerns have been addressed thoroughly,” said Rob Poole from the San Francisco Housing Action Coalition. He said scrapping the program at such a late stage “is not progress” and that “slowing this down does not build more affordable homes.”

Sonja Trauss from the San Francisco Bay Area Renters Federation agreed. Working out the kinks of the program “would be great — but guess what? [District 9 Supervisor David] Campos has been around for eight years” without addressing the housing crisis, she said, expressing “frustration” and “impatience” with the rate of progress.

That frustration was widely echoed. Laura Clark from Grow SF said housing proposals in San Francisco are often shot down because they do not solve the city’s housing crisis in one fell swoop, and that the density bonus program be viewed as one more tool in the toolbox.

“Don’t let the perfect be the enemy of the good,” Clark said. “This is going to increase the amount of affordable housing in the city.”

After consideration in February, the measure must go to the Board of Supervisors before it becomes law.