San Francisco's Mayor race has taken an unusual turn, with two opposing candidates working together hoping one of them finishes on top.

Most campaign events feature one candidate or another, but at a joint news conference on the steps of San Francisco's City Hall Mark Leno and Jane Kim announced each was backing the other as a viable second choice. "And that's why I'm running for Mayor, and that is why I'm endorsing State Senator Mark Leno as my number two endorsement," said Kim.

"I am proud and pleased to stand by the side of Supervisor Kim and to offer her my two endorsement," said Leno.

San Franciscans are among the voters who can register first second and third choices for mayor. If a candidate in the race wins a majority of first place votes then they win, just like a traditional election, but if there's no clear majority the last place finisher is eliminated and voters who supported that candidate have their ballot instantly go to their next choice. That process goes on until there is a majority winner.

Kim and Leno aim to capitalize on that and even rolled out a preview of an ad they say will appear on social media and televisions in San Francisco. With the candidates alternately saying, "vote for me and Mark Leno. Vote for me and Jane Kim. The city belongs to us, not the billionaires."

The two candidates are effectively teaming up to counter some-time front runner London Breed. Saying she hasn't sufficiently condemned outside money that has poured into the campaign on her behalf.


For her part Breed said today she's focused on her campaign. "Clearly, nothing surprises me during the political season where people make decisions to do what they feel is necessary to win over voters," said Breed.

Her campaign though was more blunt, saying ,"what's the news here? Leno & Kim's one-two strategy was announced to the world the day they orchestrated London Breed's removal as acting mayor."

To put all this in context, it was ranked choice voting that helped push former Oakland Mayor Jean Quan into office.

Quan allied herself with other candidates for mayor, aiming for 2nd and 3rd choices on the ranked choice ballot, and upset front-runner Don Perata. Quan served one term as Oakland's Mayor.