NEW YORK (CBSNewYork) — The race for City Hall has taken an eyebrow-raising twist. The teachers’ union has embarked on a stunning strategy to derail the campaigns of the two front-runners.

It’s a plan to manipulate the new ranked-choice voting system, CBS2’s Marcia Kramer reported Wednesday.

Who would have figured that a crafty mayoral candidate with a basket of troubles would attempt to dig himself out of a hole by developing a “kill switch” to hurt his poll-leading opponents?

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Meet Scott Stringer, who, in cahoots with the teachers’ union, has launched a novel strategy to siphon support from Eric Adams and Andrew Yang.

“I’m very proud to have the endorsement of our teachers. They’re going to tell their members, as they should, who’s good for public schools and who’s not,” Stringer said.

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The United Federation of Teachers sent an email to its 80,000 members urging them to vote for Stringer, whose campaign has been hurt by sexual harassment charges, and to avoid Adams and Yang like the plague in the new ranked-choice voting system. The email states:

“Do select Scott Stringer as your first choice for mayor. Don’t select Eric Adams or Andrew Yang as a choice for mayor. Any appearance on your ballot, even as your fifth choice, can get them elected.”

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The move is ideological, intended to boost the left-leaning anti-charter Stringer campaign and hurt the two more centrists candidates, who have received contributions from rich pro-charter donors.

“Both Andrew Yang and Eric Adams are supported by hedge fund billionaires and people who don’t care about equity and who don’t have the best interests of New York City’s children at heart,” UFT President Michael Mulgrew said.

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And it’s no coincidence that Stringer launched a website — City Hall is Not For Sale — to highlight the pro-charter billionaires backing the two front-runners.

“Sometimes the leadership is not speaking on behalf of the rank and file. I’m comfortable with the relationship I have with my teachers. I put them first and I believe they’re going to rank me first,” Adams said.

“I was a little hurt by it,” Yang said.

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“It’s absolutely a legitimate thing to think about if you want candidate ‘A’ to win the race, to think about how it is you’re going to keep candidate ‘B’ down in the vote,” Baruch College pundit David Birdsell said.

Which is another way of saying that in a Democratic mayoral primary, all’s fair in love, war and politics.

Under the city’s new ranked-choice system, voters have the option of picking up to five candidates in order of preference.

Marcia Kramer