It's a Tuesday morning in October, and as a second-grade class at Lowell Community Charter Public School breaks for refreshments, eager kids share their snack selections with a visiting reporter (nacho cheese Doritos and juice, chips and Gogurt).

Lowell Community sits in a funky old mill building downtown, and runs from kindergarten through 8th grade. The school opened in 2000, nearly closed a decade later thanks to low test scores, and then rebounded to become a Level 1 school, the state’s top category.

Diana Lam, the school’s interim head, says that’s not the only way Lowell Community has defied expectations.

“At this school, we enroll 27 percent of students with disabilities,” Lam said. “And you compare that to Lowell district, with 15.5 percent [students with disabilities].”

Charter opponents accuse the schools of skimming off kids who are easy to educate, leaving district schools to educate everybody else. But Lam says that at Lowell Community, that’s not the case.

“You go to English language learners—that’s another criticism,” Lam said. “Yet at our school, we enroll 55 percent of English language learners, compared to 25 percent for Lowell District.”

And yet, Lam says proudly, students at Lowell Charter regularly outperform their peers at traditional schools.

“You look also at the results—and I believe the results should matter; after all, we’re accountable for those—we also see that on every category, in ELA, in math, we outperform the Lowell school district,” she said.

For anyone weighing their vote on Ballot Question 2, which would allow Massachusetts to approve up to 12 new charter schools a year, Lam’s numbers paint an upbeat picture. But talk to Salah Khelfaoui, Lowell’s superintendent of schools, and things get quite a bit murkier.

Khelfaoui says that when you add up all Lowell’s charter-school numbers—the amount of kids who go, the tuition bill from the state, the state’s charter-school reimbursement—Lowell is taking a big hit on every charter student.

That’s because while charters do take kids with mild disabilities, the district has to cover the cost of Lowell’s most acute special-education cases—often, children who require increased staffing, or who go to specialized schools outside the district.

Because of that cost, the Lowell School District says it’s not able to spend as much on typical students as charter schools are. The difference, according to Lowell officials, is approximately $290 per student per year.

Yet when you average it all out, as the pro-charter Mass. Taxpayers Foundation did in a recent study, the per pupil cost for charter and district school students turns out to be about the same, in Lowell and elsewhere. 

“Some of the argument is driven by numbers and some of it is driven by philosophy,” said Darren Graves, an associate professor of education at Simmons College.

“Sometimes, people are just seeing this as big corporations coming in to suck away money from public schools and create a private-school industry,” Graves added. “Whereas in a lot of communities, especially communities where the public schools have been failing them, it represents an opportunity for them to have a better set of choices.”

Simply getting those two sides to agree on data is difficult, since they’ve each got their own distinct way of framing the numbers. But getting them to question their basic philosophical assumptions is nearly impossible.

Paul Georges, the head of the United Teachers of Lowell, has been running that union for more than two decades. He didn’t like charters when they first came to town in the mid-'90s, and he doesn’t like them now.

But Georges also notes, with evident pride, that Lowell’s traditional schools are working pretty well.

“It was [just] announced that we’ve got seven Level 1 schools, seven Level 2 schools, and seven Level 3 schools,” he told WGBH News. “Very few gateway cities have that designation.”

Which raises an obvious question: since Georges decried charters as a huge threat 20 years ago, what concrete negative effects have they actually had?

Given his staunch anti-charter stance, George’s answer is unexpectedly tentative.

“There’s some places where we’ve had to put off acquisition of technology, hiring technology experts or teachers to be able to utilize that,” he said. “Maybe expanded pre-K education that works so well in urban districts like this.”

Asked if he can link specific district cuts to funds sent to charters, Georges acknowledges he can’t.

“I’d say there’s correlation … I can’t just say the charter school took this money and this is what was eliminated,” he said.

Still, Georges has no doubt that if Question 2 passes, the toll exacted by charters in Lowell and across the state will increase.

In a way, that certainty is enviable. Because if you’re not a diehard partisan, the more you learn about the charter debate, the more confusing it gets.