Sonja Trauss doesn’t seem like someone who frequents cocktail parties. Genuine and attentive, yes, but she’s far more at ease debating solutions to San Francisco’s housing crisis than mingling and making small talk. However, these soirees have become a regular part of Trauss’ routine — a necessity for a candidate on the fundraising circuit. Trauss, head of the San Francisco Bay Area Renters’ Federation, is running for supervisor of District 6, a heady blend of wealthy SoMa loft dwellers and the Tenderloin’s homeless population.

As she moves around this particular evening’s event, she talks development with community housing folks and political strategy with a pair of lawyers. When someone offers Trauss a chair (she’s eight months pregnant), it surprises no one who knows her that she replies “No,” rather forcefully.

Trauss, 35, is running as a moderate in a district that has gone to progressives in the past five supervisor races. But that’s not what sets her apart. Instead, in a city where local elections can get dirty, and a candidate’s history and connections matter, Trauss is a polarizing figure whose vision for reshaping San Francisco’s development makes some see red.

Trauss wants to build, build, build — as many new housing units as it takes to bring down the ghastly cost of rent. And she thinks the buildings should be primarily in high-income neighborhoods. “Where do we want people to live?” she asks, and then answers: “We don’t really want people to live in low-income areas because it displaces people and increases the cost.”

Her base is a fervent one — and includes many in the tech field who are similarly young, new to the area and frustrated by the cost of housing.

This strategy is part of the Yes in My Backyard, or YIMBY, platform — crafted by critics of the long-standing Not in My Backyard trend in neighborhoods that reject what they perceive as undesirable change, typically forcing development like housing projects into less affluent areas. YIMBY groups have sprung up across the U.S., but in San Francisco — the country’s most expensive city to rent an apartment — it galvanized a pro-building movement, of which Trauss has become the controversial face.

Trauss grew up in Philadelphia and studied philosophy at Temple University. She worked for a local neighborhood advisory committee and as a paralegal before earning a master’s in economics. In 2011, she moved to the Bay Area and taught high school and college math.

In her new home, she noticed how people resisted development, worried that it would bring the density of Manhattan to San Francisco without significantly reducing rental costs. Having left a city losing population and taxpayers, Trauss was frustrated by the stubborn reluctance to accommodate all the people who wanted to live in the city. “Where do you think public services come from?” she asks.

Disappointed by those she describes as “anti-building” folks, Trauss started organizing for more housing development in San Francisco. She would troll the comments sections of blogs and tell people to get off their computers and into planning meetings. After Trauss founded SFBARF in 2014, she was instrumental in launching YIMBY, which consists of a political action committee, an advocacy organization and a nonprofit that sues communities for not building enough housing. In July, YIMBY won its first court case, forcing the city of Berkeley to approve a three-unit building opposed by neighbors who argued its residents would take their parking spaces. Then Trauss dived into local politics.

Her base is a fervent one — and includes many in the tech field who are similarly young, new to the area and frustrated by the cost of housing. Supporter Todd David, executive director of the San Francisco Housing Action Coalition, says Trauss recognizes that the housing shortage is also keeping the city from living up to its own message of tolerance and acceptance. “She’s probably the most honest politician I’ve ever met,” David says.

And yet that honesty, which can be a blunt weapon, isn’t an unqualified asset to her rookie campaign. “In larger races, you have all these peripherals. In this case it’s only Sonja Trauss on the ballot, and everything that entails, good and bad. It is about you,” says San Francisco political analyst David Latterman.

Trauss is known for being a straight shooter, but her outspokenness has landed her in dangerous territory. She tweeted in 2016 that “gentrification is what we call the revaluation of black land to its correct price”; in 2010, she blogged that low-income public housing tenants “usually can’t read or write.”

gentrification is what we call the revaluation of black land to its correct price. — Whirl is king😷 👑🦠😷 (@SonjaTrauss) July 12, 2016

She says she regrets what she chalks up to internet sloppiness and then adds: “The worst thing about that is the phrase taken out of context really perpetuates stereotypes that I really do not believe in. It makes me sad and frustrated and I definitely feel very sorry for it.” Still, Trauss insists, minor scandals bubble up in every election, and that the district’s voters appreciate a candidate who speaks her mind and connects with them as a community member.

Her chief opponent, Matt Haney, has experience as an elected official on the San Francisco Board of Education. Haney is garnering support from some of the district’s progressive voters who believe the building boom is ruining the city’s character, but Trauss hopes his traditional credentials will work against him. She calls herself “a realistic candidate” who appeals to people ready for a supervisor “who’s just going to be frank about what’s going on.”

With the election still a year off, the race is in its early stages, and more candidates could emerge before voters head to the ballot box next November. In the meantime, Trauss will take a break from campaigning to have her baby. And if she succeeds in her quest for more affordable housing for San Francisco residents, it could mean more space for her and other growing families.