Portland City Hall.

PORTLAND, Maine — Officials from Maine’s largest city advanced an effort that would expand ranked-choice voting to school board, City Council and other municipal elections onto the ballot in March.

The unanimous Monday night decision was another milestone for the state, which has become a model for the use of ranked-choice voting nationwide. It would pin the referendum to a ballot that also contains the Democratic primary candidates for the 2020 presidential election.

“It’s a credit to the City Council to put the question on the March ballot,” said Anna Kellar, chair of the Fair Elections Portland campaign.

An effort by Kellar and others to collect signatures fell about 75 signatures shy of the 6,655 needed to get on the ballot this past summer. The threshold was indexed to the turnout to the previous gubernatorial election.

“We fell just short, but we felt like there was strong support in the city,” Kellar said, noting that 300 disputed signatures could have broke the other way and pushed the effort over the threshold.

On Monday night, councilors briefly considered putting the question on the ballot next June, which already contains a charter commission vote. But Kellar and others argued that the council keep the initial date in March, expecting a high turnout for the Democratic presidential primary and people’s vetoes.

A vote to amend the city charter requires 30 percent of the city registered voters to pass. Kellar said that such a threshold would not have been met in any previous June election in Portland.

“I think it’s probably right that we’d hit the threshold for qualified voters in March and we might not in June,” Councilor Jill Duson said.

Other advocates praised the effect of ranked-choice voting, also known as instant-runoff voting, on political campaigns, as illustrated by the city’s recent mayoral race.

“Without ranked-choice voting, [Portland mayoral candidate] Travis Curran would have spent the entire campaign answering questions about how he’d be taking votes away from Ethan Strimling,” said Steven Biel of the advocacy group Progressive Portland.

Because of ranked-choice voting, Biel argued, Curran could talk about issues important to him, and to voters.

The first City Council meeting after the mayoral election was packed with important issues, including a resolution that sets parameters for the next city shelter and an amendment as to whether to prohibit the use of facial recognition technology among all employees of the city. In the end, it turned out to be largely preparatory, as City Council opted to postpone or otherwise refer decisions on several items to the incoming council.

Portland has used ranked-choice voting in its three mayoral races since restoring the popularly elected position in 2011, but it hadn’t expanded it to any other city races. Only the 2011 race went into an instant runoff.

Maine became the first state to use ranked-choice voting in statewide races after a 2016 referendum that has only applied to primaries for state offices and general elections for the U.S. House and U.S. Senate since 2018. The Democratic-led Legislature expanded it to presidential elections this year, putting Maine on track to be the first state to allocate electors that way in November 2020.

The method is likely popular in the liberal bastion of Portland. An exit poll from the Bangor Daily News and FairVote in November 2018 found a narrow majority of Mainers wanted to expand the use of ranked-choice voting. Voters split heavily along party lines, with 81 percent of Democrats wanting to expand it and 72 percent of Republicans wanting to stop using it altogether.