Portland would become one of a small group of U.S. cities, and the first in Maine, to allow legal noncitizen immigrants to vote in local elections as part of Mayor Ethan Strimling’s ambitious push for a progressive set of new policies.

But even if the full City Council embraces the idea, it won’t be simple to implement. It would require a citywide referendum and possibly the approval of the Legislature and Gov. Paul LePage.

A similar proposal failed at the state level and in Portland several years ago. Now the idea is one of several initiatives outlined by Strimling aimed at improving school facilities, helping immigrants and adopting new requirements for paid sick leave and affordable housing.

Strimling’s progressive vision stands in sharp contrast to the priorities of the governor and President-elect Donald Trump. It also is a departure from the goals outlined last week by the city manager. It’s unclear how many of Strimling’s initiatives, if any,will be adopted by the City Council, which will meet Jan. 23 to establish its own goals for the coming year.

Strimling said last week that he didn’t have any specifics about which legal noncitizens would be allowed to vote, and did not know what legal steps would be required to implement the idea. He expects to refer the issue to the council’s Nominations Committee for further discussion.

“It’s a big step,” Strimling said. “I expect us to take our time to get it right and bring in as many voices as we can.”

The proposal was cheered by immigrant advocates.

“We would support people with legal status having the right to vote and having say about what’s happening in their community,” said Sue Roche, executive direct of the Immigrant Legal Advocacy Project, a nonprofit that helps immigrants seeking political asylum navigate the legal process.

Roche said immigrants granted permanent residency have to wait five years before they can become citizens. If someone is seeking political asylum it can take years longer, she said.

Portland first sought to expand voting rights to noncitizens in 2009, when Sen. Justin Alfond sponsored a bill that would have allowed municipalities to let noncitizens vote on local issues.

Many opponents argued that the Maine Constitution prohibits noncitizens from voting, but Attorney General Janet Mills said in a letter to the Legislature’s Legal and Veterans Affairs Committee that the provision only applies to state and federal offices, not municipal elections.

Secretary of State Matthew Dunlap said in a letter to the committee that noncitizen voter registration would need to be maintained separately. That was one of the reasons the initiative was opposed by the Maine Municipal Association. The lobbying group for towns and cities was concerned about the complexity and costs of running separate voter rolls and argued that the Legislature should abolish the citizenship requirement statewide.

“I think those underlying issues would still give our legislative policy committee some pause,” said Kate Dufour, senior legislative advocate for the municipal association. “If the state is interested in advancing this policy, it should do so for everybody.”

A year after Alfond’s proposal was struck down by the committee and full Legislature, Portland’s Charter Commission took up the cause. But concerns about whether Portland could allow noncitizens to vote without enabling legislation, along with the prospect of a court challenge, prompted the committee not to put the question to voters.

But the measure made the ballot anyway after immigration advocates, led by the League of Young Voters, collected more than 4,500 petition signatures. That November, 52 percent of voters opposed the proposal, which lost by roughly 1,200 votes.

“I’m willing to bet that Portland has come a long ways over the past seven years,” Strimling said last week.

Nationally, only nine U.S. communities allow nonresidents – both documented and undocumented – to vote in local elections, including seven jurisdictions in Maryland, said Ronald Hayduk, an associate professor of political science at San Francisco State University and author of “Democracy for All: Restoring Immigrant Voting in the U.S.”

In the past two years, both Cambridge, Massachusetts, and Burlington, Vermont, voted to expand voting rights, but they have been unable to implement those policies because their respective state legislatures have not enacted enabling legislation.

Dufour, of the municipal association, said she believes the Maine Legislature would also have to pass enabling legislation before noncitizens in Portland could vote.

The city’s corporation counsel, Danielle West-Chuhta, said she has informed the mayor that the change would require a charter amendment, and that she agrees with prior legal opinions that such a move would be likely be challenged in court.

According to state law, a city charter can only be changed through a Charter Commission, which would send a recommendation out to voters.

Once a commission is established, all areas of the charter are open to review, including the future of the elected mayor position, which has been a source of tension in City Hall since it was established five years ago.

While allowing noncitizens to vote may seem like a radical idea, Hayduk said that’s not the case. He said immigrants were allowed to vote in local, state and, in some cases, federal elections in 40 states until the 1920s, when waves of immigrants prompted those states to tighten voting rules.

In 1969, New York City was the first community to reinstate that right for parents of public school children, but the law was nullified in 2002 when NYC consolidated its school districts, Hayduk said. Chicago started allowing parents of schoolchildren to vote in 1989, he said.

Last year, San Fransisco – after two failed attempts – extended voting rights in school board races to all residents regardless of immigration status, and Hyattsville, Maryland, extended immigrant voting rights in local elections, Hayduk said.

Noncitizen voting initiatives typically generate vigorous debates in communities, he said.

“It’s a really rich, robust and, yes, contentious discussion,” Hayduk said. “It goes to the heart of what is America who is an American.”

Strimling’s proposal comes at a time when the debate on immigration has reached a fever pitch. Trump has talked about banning Muslims from entering the country, deporting millions of undocumented immigrants and establishing registries for Muslims.

Immigrants have been under attack from Augusta as well, with LePage repeatedly seeking to disqualify asylum seekers from receiving emergency assistance. He also has made the unfounded claim that immigrants are riddled with diseases.

Both men have criticized so-called “sanctuary cities,” which are communities that have a policy of not assisting immigration officials in identifying and deporting illegal immigrants. LePage has labeled Portland a sanctuary city, even though the city’s police force assists federal immigration authorities when investigating crimes, but otherwise doesn’t ask about immigration status.

“In the end, honestly, I don’t care if politicians try to label us a sanctuary city or not,” Strimling said last week during his State of the City address, which also called on businesses to establish “Hate Free Zones” for immigrants, and for residents to shop at Muslim-owned stores as a way to fight back against vandalism at one of the stores on Christmas Eve.

“I only care that our residents know that Portland provides the sanctuary, with a small ‘s,’ that allows for all of us to feel safe,” he said. “Because even in the face of threats from Washington, D.C., we must not retreat from our values we hold so dear.”