BOSTON — Senate President Stanley Rosenberg touched a nerve on Monday when he painted a bleak picture of the prospect of advancing charter school expansion legislation through the Senate this year, but his read of fellow senators jibes with what even supporters of charter schools are hearing from their Senate colleagues.

Rosenberg described the possibility of the Senate acting on charter school legislation as "very much an uphill battle," and asserted that in his home district constituents oppose adding new charter schools. He would not say whether that means he would vote against a bill.

Great Schools Massachusetts, the group driving a 2016 ballot campaign to expand charter schools, punched back on Tuesday, directly challenging Rosenberg's reading of his district.

The campaign said there were 569 children "currently stuck on charter school wait lists" in Rosenberg's district and more than 1,000 charter school students enrolled in his district, "demonstrating significant demand for access to public charter schools."

The group also said it had gathered signatures from 296 individuals in Rosenberg's district for an online petition urging the Senate to vote to lift the cap. The signatures represent a fraction of a percent of the 159,000 people the Amherst Democrat represents in the Legislature.

"Today, 5,000 kids are stuck on waiting lists in Holyoke and Springfield, cities that border Senate President's district. It is time for Senate President Rosenberg to listen to the needs of all Massachusetts families," Michelle Hernandez, a Springfield parent and member of Great School Massachusetts, said in a statement.


Rosenberg's office declined to respond to the group's critique, but an aide said the president came to his opinion of his district's view on charter schools through interactions with residents and nearly 30 years' experience representing those communities on Beacon Hill.

After initially saying he hoped to reach a conclusion by Thanksgiving, Rosenberg now expects to determine by the end of the month whether a majority in his branch could support an expansion of charter schools in Massachusetts this year. The Senate rejected a charter bill in 2014, and Rosenberg said on Monday, "In order to move forward, we would have to be able to thread a needle."

During a series of recent meetings, many senators have expressed concerns about the funding of charter schools and raised questions about whether they negatively impact the finances of traditional public schools. Rosenberg said he still has five to seven more Democratic senators to speak with, but described the concerns as "all over the map."

Sen. Michael Rodrigues, D-Westport, one of the nine senators who voted for the House's charter expansion bill in 2014, said he supports raising the cap by whatever means necessary, but believes it will fall into the laps of voters next November to decide.

"I am a supporter of raising the cap on charter schools. I support the governor's bill. I support the ballot question. I would support a reasonable compromise if one were able to be cobbled together. I don't see it happening though," Rodrigues told the News Service.

Despite whatever his personal opinions might be, Rodrigues said he believes Rosenberg is making a good faith effort to put together a compromise that could pass the Senate. He just doesn't have much confidence it will come together.

When charter school legislation surfaced in 2014, only 13 senators supported version of the House bill intended to win over reticent senators, and support fell to just nine when a vote came up on the House bill alone.

Since then, two of the core charter school supporters — former Sens. Barry Finegold and Robert Hedlund — have left the Senate, and East Boston Sen. Anthony Petruccelli, another charter backer, is preparing to depart in two weeks. There are six new senators who weren't members in 2014.

"On issues like this, we should give it our best attempt to try to put together a compromise, but I don't see it happening. I really don't. I feel very strongly that I am in the minority in my caucus," Rodrigues said, explaining that he doesn't think any of the meetings with proponents and opponents changed any senators' minds.

Sen. Linda Dorcena Forry, D-Dorchester, and another of the Senate's charter school supporters, believes leaving the issue for voters to decide would be a mistake given the potential ramifications of the ballot proposal to authorize up to 12 new charter schools a year outside the cap.

"I'm hopeful we can come up with something we can get down because to leave it up to the ballot and eliminate the cap completely would be a significant issue for cities and town around the commonwealth," Forry said.

One senator who could change the trajectory of the debate, according to several involved in the branch's discussions, would be Rosenberg himself. While the new leader has pioneered a more inclusive style of leadership, putting his foot down to rally Democrats around a compromise bill would change the dynamics, they said.

Asked on Monday about the chance to set a course for the Senate on charter schools, Rosenberg suggested he was not interested in twisting arms.

"I have an opportunity to stake out a position for myself and my district. My district does not want to see any more charter schools. Each senator on this issue has to look very deep into what's on their minds, their constituents' minds and they're going to make the decision for themselves and our job as Senate leadership is to figure out if there's a majority and if there a majority for a bill, what would have to be in the bill," he said.

Sen. Donald Humason, R-Westfield, who has also voted as a member of both branches to support charter school expansion, said that after numerous discussions among Democrats and Republicans he "couldn't fault" Rosenberg if the president decided to pull the plug at the end of the month and allow it to advance to the ballot.

"There's certainly been no shortage of conversation about the issue, but I haven't seen a lot of movement," Humason said. "If I were a betting man, I'd say I'm not sure how we get there based on what I've seen."