In a devastating loss for supporters of charter schools, Massachusetts voters on Tuesday voted against a ballot question that would have allowed the state to approve up to 12 new or expanded charter schools a year, outside of an existing cap.

With 40 percent of precincts reporting, the No on 2 effort was ahead, 62 percent to 38 percent. The Yes on 2 campaign sent out a statement conceding at 10:15 p.m.

The vote was deeply personal to voters like Harneen Chernow, the mother of two Boston public school students, who held a No on 2 sign at a West Roxbury polling place.

"I'm very concerned about the impact this question, if it passes, will have on the finances of Boston public schools," Chernow said. "It was designed to add more schools without adding more resources."

"Librarians have been cut, athletics have been cut, some of the foreign languages have been cut, some of the guidance counselors and support that help cement a school community have been cut," Chernow said. "We're very concerned about what this will mean in terms of continued cuts in the schools."

Current law caps the money that school districts can spend on charter school tuition. Essentially, this limits the number of charter schools that can open in each district. Eight districts have hit their cap, including major urban areas like Springfield and Boston. At the same time, more than 32,000 students are on waiting lists for charter schools.

The ballot question would have given priority for the new schools to charters in the 25 percent lowest performing districts and in districts where there is parent demand for new options. New approvals could have expanded charter school enrollment by up to 1 percent of total public school enrollment annually. New schools could have been approved as soon as Jan. 1, 2017.

Supporters of charter school expansion say more charter schools are needed to give families in urban districts, many of whom are black or Hispanic, more choices. Many of the public schools in these areas are low-performing.

Rose Leblanc, of Boston, is homeschooling her six-year-old son while he sits on a charter school waiting list. Leblanc, who lives in the South End, said she refuses to send her son to a failing public school in an unsafe neighborhood.

Charter schools, Leblanc said, are "giving kids who never had an opportunity, who are in failing public school systems, a chance to actually have the opportunity."

"Because there's so many people that want their kids in a safe, better school, with a better curriculum, smaller class sizes...the waiting list is so long," Leblanc said.

But when a student leaves a district school to attend a charter school, the state money to educate that child moves to the charter school. Opponents of charter school expansion say allowing more charter schools will devastate the budgets of traditional public schools, which will lose money without eliminating many of their fixed costs, such as building maintenance and librarians.

While some lawmakers have been trying for years to lift the charter school cap, the Legislature has been unable to agree on a legislative fix.

An enormous amount of money was raised by the campaigns, allowing both sides to flood the airways with advertising. Charter school supporters raised $26 million and opponents raised $15 million.

The pro-charter school money came from a mix of Massachusetts corporations, individuals working in the financial industry, out-of-state donors like the Walton family who owns Wal-Mart and former New York Mayor Michael Bloomberg, and education reform groups that do not have to disclose their donors. The anti-charter school money came primarily from teachers unions.

Gov. Charlie Baker, a Republican, was a major supporter of charter school expansion, campaigning and fundraising on behalf of the ballot question.

The Democratic State Committee voted to oppose charter school expansion. Also opposed were some of the state's prominent Democrats including Boston Mayor Martin Walsh and U.S. Sen. Elizabeth Warren.

For many voters and volunteers, the stakes were high and personal. Percreena Cherrie, of Roxbury, sends her 8th grade daughter to a charter school. The school, KIPP Academy, could not open a high school because of the cap. "If there wasn't a cap.... I could just send her through to high school," Cherrie said. "But now I'm going through the whole process, back on waiting lists, looking for a good high school." Cherrie is looking for money to send her daughter to a private or Catholic school, because she does not think her daughter will get a good education in the public schools.

For Tonya Tedesco, of West Roxbury, her no vote was equally personal. Her daughter attends a Boston public school. She worries that if Boston public schools lose money, it will impact not only the schools but public services, if the city has to divert more money to education.

"Twelve schools a year is not the solution for the challenges facing the struggling districts," Tedesco said.

Even individuals in cities not as directly impacted reflected on their own experiences. Susie Mees Longfield of Cambridge used to teach in the Belmont public schools. Her children attended private schools. She voted yes on Question 2.

"I felt like we had the privilege and the option to send them to public or private, and a lot of people don't have that choice," Mees Longfield said.