Voters decided to uphold driver’s licenses for undocumented immigrants. But the margin was close.

Marlene Sabido, a supporter of Yes on 4, donned a driver's license sign at rally Tuesday night.Carlin Stiehl for The Boston Globe

While most Massachusetts Democrats ran away with their races Tuesday night, a ballot question in which voters decided to retain a divisive law allowing undocumented immigrants to get driver’s licenses was decided by just 7 percentage points

The result, according to some experts, suggests that the Commonwealth is still polarized when it comes to immigration reform and policymaking.

According to a Globe analysis, more than 100 cities and towns that voted for Democrat Maura Healey, who trounced her Republican opponent for governor by almost 30 percentage points, voted to repeal the new law.

The biggest clusters of opposition to Question 4 were in the middle of the state, along the New Hampshire border, and on the South Shore. Meanwhile, voters from metropolitan areas like Boston, Springfield, and Worcester were supportive, as were cities with large immigrant communities like Lowell and Lawrence.

“You have two very distinct Commonwealths here when you look at this map” breaking down the results, said Robert Forrant, a history professor at UMass Lowell who focuses on state history and immigration.

The narrow results reveal that while the electorate quickly got behind Democrats running statewide, voters are perhaps more socially moderate or even more conservative than commonly believed.

“It somewhat confirms the sort of thin veneer on a lot of cultural social issues,” Forrant added. “We are a liberal state and the election of Maura Healey is an important moment . . . but on an issue like this, there is still pretty deep division.”

Question 4 was decided months after Martha’s Vineyard opened its doors to two planeloads of immigrants who were dispatched to the island by Florida Governor Ron DeSantis in a political stunt that thrust Massachusetts into the national immigration debate. More recently, the state has been grappling with an influx of migrants largely from Latin America and Haiti, and has resorted to putting some families in hotels as homeless shelters reach capacity.

Both sides on the ballot question say a confluence of factors led to the result.

Those in the “no” camp say they were outspent by advocates who were bankrolled by the Service Employees International Union and insurance companies, which raised $3.5 million. (The opposition raised about $219,000.)

If all things were equal, the law would have been repealed, said Wendy Wakeman, a GOP activist who helped coordinate the signature-gathering.

“We were outgunned,” she said. “It was an uphill climb.”

Those on the Yes side said they were caught off guard when the GOP-led effort to repeal the law solicited 100,000 signatures in two months to get the question on the Nov. 8 ballot.

State Senator Adam Gomez and supporters took the stage to celebrate a likely victory on Tuesday night.Carlin Stiehl for The Boston Globe

The law, which goes into effect next summer, allows people without legal immigration status to obtain a license by providing two documents that prove their identity, such as a foreign passport, birth certificate, or marriage certificate. It passed after Massachusetts legislators voted to override a veto from Governor Charlie Baker, who said the measure could threaten election security, among other concerns.

Those who have worked on immigrants’ rights issues said the two decades of advocacy and coalition-building to get the law passed created enough of an organized network of volunteers to push back against the GOP-led effort to undo the law, even though they had only weeks to act.

And because the question qualified for the ballot too late to be included in an informational pamphlet sent by the secretary of state, an explanation was never mailed to voters.

With more time to educate voters, supporters of the measure say, the margin would be wider, those in favor of upholding the law argue.

“We didn’t have a plan for this when we won the bill,” said 32BJ SEIU Executive Vice President Roxana Rivera, one of the leaders of the coalition that worked to uphold the new law. “Time was against us in every which way,” she said.

Senator Brendan P. Crighton, a Lynn Democrat and bill cosponsor, said the years of research on the issue showed “the facts were on our side.”

If more people knew the facts, the margin of victory would have been greater, he said.

“This was a really short time crunch for a campaign to come together and get information out to millions of voters,” Crighton said. “But Massachusetts residents stood on the side of safer roads and equality. They made a strong statement about who we are.”

Public opinion on immigration issues has shifted over the years. A 2005 Suffolk University poll found that most voters — nearly 80 percent of them — did not support allowing Massachusetts residents without legal status to pay in-state tuition at state colleges or universities.

A 2010 poll found that 84 percent of Massachusetts voters supported an Arizona law that cracked down on illegal immigrants. In the same poll, 84 percent of residents said the state should force people to show proof of citizenship or legal status to seek state benefits like public housing or other assistance.

In 2014, meanwhile, a Suffolk poll reported that nearly 70 percent of Massachusetts voters did not support giving driver’s licenses to undocumented immigrants. On the ballot Tuesday, about 54 percent ended up voting for the law.

“The issue of immigration is an incredibly complicated one . . . both sides are looking at it to a certain degree of what’s fair,” said Forrant, the professor. “The love-hate relationship is right there on the map.”