Mayor Thomas Menino is weighing a City Council-approved proposal that pushes the Polish Triangle and Carson Beach into Dorchester’s District 3, while splitting Lower Mills between Districts 3 and 4. The re-drawn map plan flows from 2010 US Census numbers showing the need for district boundaries to be shifted, where they will remain for the next ten years.

A coalition of civic and community groups, including NAACP-Boston and MassVOTE, says it plans to file a lawsuit over the proposed new alignment, which was passed by a 7-6 vote, if it is signed into law. “We are concerned that the map passed by the council today will unlawfully pack minority residents into district four, thus limiting their voting strength in the surrounding districts,” Rahsaan Hall, deputy director of the Lawyers’ Committee for Civil Rights and Economic Justice, said in a joint press release put out by the coalition after the Council vote that also urged Menino to veto the proposal.

“I want to take a look...and make sure all of the neighborhoods of Boston have equal representation,” Menino told the Reporter after an event in Roxbury. “That’s what I’ll be looking for.”

Pressed on whether there could be any deal-breakers for him in the plan, Menino said, “It’s a City Council action and I have to look at the City Council action that’s presented to me. I mean, there’s a district that Charles Yancey represents – 98 percent persons of color. That’s a little cracking and packing, I would think.”

Menino was referring to District 4, which Yancey has represented since 1983. The district has an extremely high concentration of people of color, which coalition activists put at 95 percent.

District 2 Councillor Bill Linehan, who chairs the committee tasked with drawing the redistricting map, said in a speech to colleagues that his proposal does not pack or crack any districts.

Voting in favor for the map were Linehan; City Council President Stephen Murphy; District 3 Councillor Frank Baker, who represents Dorchester; District 5 Councillor Rob Consalvo, who represents part of Mattapan; and District Councillors Mark Ciommo, Sal LaMattina, and Matt O’Malley.

Voting against the map were City Councillors At-Large Ayanna Pressley, Felix Arroyo, and John Connolly; and District Councillors Charles Yancey, Tito Jackson (District 7), and Michael Ross (District 8).

Linehan asserts that the map, which moves 12 precincts in 7 council districts, builds on past redistricting efforts. “I was using the gradual change and adjustment from past redistricting plans,” Linehan said during a sit-down in his City Hall office. Citing “public discussions” and “public intentions,” he said that he had been hoping for nine votes in favor of his plan. But because of Open Meeting Law restrictions, he said, he could not engage in a poll of members. He added that he hoped the mayor would approve the map, since six out of the nine district councillors – two-thirds – supported his plan.

Under his map, Linehan said, District 4 has fewer people of color than with last map. “It is a change in the right direction,” he added. He also noted that District 4, made up of Dorchester and Mattapan, is surrounded by other districts that are majority-minority: District 3, which includes Dorchester; District 5, made up of Hyde Park and parts of Mattapan; and District 7, which includes parts of Roxbury, Dorchester, and the South End.

In the interview, Linehan, who would give up the parts of Dorchester he represents, including the Polish Triangle, pushed back on the suggestion that he added to his vote total from 2011, when he won reelection by 97 votes.

For its part, the voting rights coalition notes that Linehan took out the most diverse precincts currently in his district, turning District 2 into the least diverse in the city. Linehan now represents parts of Dorchester, all of South Boston, Chinatown, and parts of the South End.

“Because I had a close election in 2011, observers who don’t favor the outcome could construe that it was not an objective effort on my behalf,” acknowledged Linehan, but he said he was “extremely objective” as chair of the redistricting committee. “My district has changed the most,” he said, in giving up the most precincts in the process while noting that he was also picking up a precinct with 6,000 new people.

But other councillors argue that the Council should take another shot at redrawing the districts, particularly since the threat of a lawsuit looms. “A lawsuit alleging that the city did not go far enough in ensuring an equitable voice and opportunity for residents of color is a terrible thing for this body, for our city, and most importantly for residents,” Pressley said before the vote. “I ask that we go back to the drawing board one more time.”

Baker defended Linehan’s map. “I just think that map had been vetted out,” he said. “It had been there for quite some time, it had been shopped around.”

Baker also noted that the map activists were circulating completely overhauled the district lines for Dorchester’s Districts 3 and 4, with Dorchester getting divided north-south instead of the current east-west divide. “The map that they had would have totally decimated Dorchester,” Baker said. I couldn’t sign onto that.”

Former City Hall aide James Chisholm, now a vice president at Resolute Consulting, said the 7-6 vote could be charted from the outset. He noted that redistricting activists were unlikely to get behind a Linehan plan that didn’t increase the chance for more minority-majority districts.

But the city’s geography – which ensures the existence of council districts for Allston/Brighton, East Boston, Charlestown, and South Boston – makes redrawing the boundaries a difficult task and councillors are not going to accept a plan that will end up with them being redrawn out of office, he said. “I think part of the problem there is no simple solution here,” Chisholm said.

One potential way to go, he said, is for the city to return to a completely city-wide model, where all 13 councillors serve at-large. Currently, there are nine district councillors and four councillors at-large. The elections of Arroyo and Pressley, who topped the at-large ticket in 2011, have shown “candidates of color can win citywide, said Chisholm, a former Pressley aide.

As to mapmaker Linehan, asked what he plans to do if Menino vetoes the map, he answered: “I’ll take it as it comes.”