After narrowly losing to London Breed in 2016, Dean Preston eked out a win in the District 5 supervisor race on Saturday, taking the seat from Vallie Brown, the mayor's appointee.

Preston declared victory on Saturday, as Mission Local reported, with 170-vote lead over Brown as ranked-choice ballots were tabulated and provisional ballots continued to be counted. Though still not final, this looks to be the narrowest ranked-choice victory in city election history.

Incidentally, the city's Department of Elections site still shows Brown having a 49-vote lead, and Brown has yet to post anything, concession-wise, to Twitter. Brown's campaign consultant, Leo Wallach, told the Chronicle Saturday that his team was “still evaluating the results, and making sure everything is 100 percent resolved.”

As a Democratic Socialist, Preston will tilt the balance of the Board of Supervisors even further to the left than it already is, and his win removes a vote from the Board that was consistently loyal to the mayor. Preston previously ran against Breed for the District 5 seat in 2016, and by all accounts he is likely to be a foe of the mayor's on the board. His declared areas of focus are tenants' rights and affordable housing, creating a homelessness commission to oversee the Department of Homelessness, and during his campaign he pledged to put a measure on the March 2020 ballot that would make Muni free for all by 2025.

The Chronicle quotes Preston at his would-be victory party last Tuesday saying, "What is missing in so many campaigns is a vision of what this town could be if we did not surrender to the darkest forces of capitalism and neo-liberalism. We are going to change [this town] with mass mobilization, democratic socialism and fearless advocacy for the things we know are right."

Speaking to Mission Local, Preston said, "This was a low-turnout, off-year election, and we ran an unapologetic, progressive, Democratic Socialist campaign. It’s exciting to win any race. And especially one like this."

Along with newly elected District Attorney Chesa Boudin, Preston's election brings the ideological leanings of City Hall further to the left — though neither candidate won a plurality of first-choice votes, and both benefited from the ranked-choice system in this election.

Preston will face re-election in just one year's time — this was technically a "special election" for District 5 after the mayor appointed her successor when she took the mayor's job last year, and her original term is up in 2020. It remains to be seen if Vallie Brown will run again, though that seems likely. And Board of Education President Stevon Cook announced last week his intention to run for the seat as well.