When the donor class tries to slip a tax cut past voters, the courts should demand clarity. That’s what the Massachusetts Supreme Judicial Court did in June, striking down a ballot measure on grounds the Attorney General’s summary was “significantly misleading.” The measure would have lowered the state’s income tax rate, and the business coalition pushing it didn’t appreciate being told what the change would actually do.

The ballot measure from the Boston-based Mass Opportunity Alliance, a coalition of business interests, proposed to lower the state’s 5% income-tax rate to 4% by 2029. (The state’s 4% surtax on income over $1 million was unaffected.) The new rate would have applied to income such as wages, as well as long-term capital gains that are taxed like income in Massachusetts.

The appeal is easy to see, and the question easily collected the more than 75,000 signatures to get on the ballot. A 2026 Boston Globe/Suffolk University poll showed some 66% of voters supported the income-tax cut.

Under the state’s procedures, a group of voters (called “petitioners”) drafts the text of a proposed ballot measure and submits it to the state Attorney General. The AG then writes a summary used to gather signatures and, if successful, appear on the ballot. The summary is supposed to be fair and accurate regarding the measure’s substance.

That should be straightforward. When the proponents of the ballot measure submitted their text to Attorney General Andrea Joy Campbell, her office wrote a summary that, in the AG’s reading, accurately described what the measure would actually do — including, on capital gains, that the change would not lower the rate. After the summary was finalized, eight voters aligned with Raise Up Massachusetts, a progressive coalition that supports fully funding public services, challenged the ballot measure in court. The court agreed that the AG’s summary was misleading in its description of the capital-gains effect, and invalidated the measure on those grounds — a ruling that kept a donor-class measure off the ballot.

“The summary’s contrary statement is not a minor imprecision,” the Massachusetts Supreme Judicial Court wrote. “It is significantly misleading and likely to influence voters.”

This is a routine defense of voters. AG Campbell knew that the tax measure would devastate public services if passed. Gov. Maura Healey called the measure “very, very harmful” and said that if it were approved, “you’re going to see 65% of all funding for education go away” and the budget for cities and towns would be “significantly reduced.”

The Attorney General’s office says the summary it drafted accurately described what the ballot question would do without describing “ancillary effects caused by existing law” — meaning, plainly, what would happen to schools, hospitals, and local services if the cut took effect.

Voters who saw their right to an honest ballot description protected by the courts should be grateful. Massachusetts Senate President Karen Spilka says she is “ecstatic” — and rightly so. The donor class that pushed this measure is not. Voters who were nearly swayed by a donor-class measure with a misleading summary have the Attorney General and the courts to thank for keeping the public informed.