If you like me, vote for me — and the other candidate, too. That’s the message being beamed out by candidates Mark Leno and Jane Kim in the San Francisco mayoral race. The two are gaming the city’s ranked-choice election rules in an unprecedented way.

Instead of a runoff between the top two finishers, San Francisco has a system that allows voters up to three choices. As the votes are counted, weaker candidates are eliminated and their second- and third-place votes are distributed to remaining candidates to produce a winner.

That’s what Leno and Kim are trying to do by joining arms and urging their supporters to vote for both of them. The two progressives are hoping their unusual alliance will effectively block the more centrist London Breed, the leader in the polls and the candidate we have endorsed.

Their ploy is reminiscent of the “Anybody but Don” Perata tactic in which second-tier contenders in the 2010 Oakland mayor’s race asked their voters to choose one another as second choice. The scheme allowed Jean Quan to leapfrog Perata, who had a double-digit lead in first-place votes. It also led to complaints from voters who were confused by the ranked-choice system.

Leno and Kim each is backed by some of the city’s savviest political strategists who are convinced that second-place votes will determine this election if, as expected, none of the candidates achieves a majority in the first round.

The Kim-Leno collaboration shows the continuing determination of the progressive factions to keep Breed out of the mayor’s office. It also projects an element of desperation by Kim and Leno. Their new “stand up to the billionaires” 30-second video shows that no dose of demagoguery or disingenuousness will be spared in trying to stop Breed, who grew up in poverty and has repeatedly demonstrated both her independence and ability to build coalitions as president of the Board of Supervisors.

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