A voter examines a ballot at an early voting location in Worcester, Mass. (Steven Senne/Associated Press)

MASSACHUSETTS HAS long enjoyed a reputation as a national leader in education. A pioneer of school reform, it boasts a record of impressive student achievement. It was sad to see that reputation tarnished with the rejection in Tuesday’s election of a measure that would have allowed for an expansion of public charter schools.

The state’s existing charter schools have delivered strong academic results, and thousands of parents are on waiting lists in the hope of getting their children into one of these schools. Unfortunately, those facts got lost in a campaign of disinformation waged by the philosophical foes of charters, primarily the public teachers unions that see the issue in terms of threats to unionized jobs.

At issue was a ballot measure that asked whether the state should be allowed to approve up to 12 new charter schools or larger enrollments at existing charters each year, not to exceed 1 percent of the statewide public school enrollment. Only nine communities would have been affected, and it initially seemed the measure would be approved. But debate became inflamed with a pricey ad war that became a proxy for the national debate about charters. It also became partisan: Republicans made it all about the ideology of choice, and Democrats claimed it would undermine public education.

In fact, charter schools are public schools, and they take money away from traditional schools only in proportion to the number of students they attract. Not all charters succeed any more than all traditional schools succeed. But Massachusetts, with a rigorous approval process, is noted for the high quality of its charter schools, and especially in poor city neighborhoods they have performed well. It seems more than odd for people who call themselves progressive to celebrate the denial of an option that poor parents desperately want.