Super PACs are spending big on attack ads in Boston mayor's race

Political fundraising groups have funneled hundreds of thousands of dollars into ads for the Boston mayoral race, setting the stage for what could be the most expensive — and perhaps most contentious — election for the city in recent memory.

The Bold Boston Super PAC that supports Mayor Michelle Wu has raised $743,000 so far this year, according to campaign finance disclosures. The Your City Your Future Super PAC that supports Josh Kraft, Wu’s top challenger, has raised a whopping $3.1 million in its bid to unseat an incumbent Boston mayor for the first time since 1949. 

Both groups are spending much of their money on attack messages pushed out through texts, billboard trucks, cable TV, streaming, radio and more. At the same time, the two candidates are increasingly trading barbs over transparency, city policy, and campaign finance itself.

Retired UMass Boston political science professor Mo Cunningham summed up the tenor of the race in a word: “negative."

“The next five months are going to be negative, overwhelmingly so,” he said.

The Wu-aligned Bold Boston Super PAC is running a 30-second ad that opens with two images: a closeup up of a red “Make America Great Again” hat and, next to it, the face of Kraft.

“Hey Boston,” a man’s voice says. “Trump donors gave big to Kraft's Super PAC. That's right, Kraft and his MAGA friends are attacking Michelle Wu to try to buy the election.”

Kraft has criticized President Trump for his “temperament, judgment, ethics, and character.” But Kraft’s father — billionaire New England Patriots owner Robert Kraft — has supported Donald Trump. And the pro-Wu Super PAC ads remind voters that much of the money flowing into Kraft’s camp has come from donors who back Trump.

Bold Boston's ads — ringing in at $375,000 through July 7, according to spokesman Kevin Ready — are an answer to another attention-grabbing ad released by the pro-Kraft Super PAC, called Your City, Your Future.

“We tried to tell Mayor Wu: her ideas would only make things worse but she ignored us,” a woman’s voice says over a still image of Wu. The Super PAC goes on to criticize the mayor’s handling of bike lanes, the White Stadium renovation project in Franklin Park and Boston Public Schools.

While individual campaign donors can only give up to $1,000 a year to a mayoral candidate in Boston, Super PACs (also known as “independent expenditure only committees”) can raise and spend unlimited sums of money — so long as they don’t coordinate with candidates or their campaigns.

Much of the money supporting the Kraft-aligned Super PAC has come from ultra-wealthy donors with ties to his family. A pair of million-dollar donations have come from New Balance chairman and Republican mega-donor Jim Davis, and another billionaire, Michael Rubin, chief executive of the Fanatics sports merchandise and betting empire. Asked whether he agrees with the negative tone of the Super PAC’s ads, Kraft emphasized the distinction between his campaign and Your City, Your Future.

“Look, I have nothing to do with the [Independent Expenditure]” group, he said, without using the Super PAC's name. “I’m focused on my campaign, running against an incumbent, and that’s a lot of work on the day to day.”

Some of the top donors for the Super PAC supporting Wu are unions and environmental groups. But the largest contribution came from billionaire Amos Hostetter, the cable TV magnate and co-founder of the Barr Foundation. In March, he gave $150,000 to the Environmental League of Massachusetts Super PAC, which in turn gave $175,000 to Bold Boston.

(As a disclosure, the Barr Foundation also has contributed to WBUR’s arts and culture coverage).

In her last election, Wu urged Super PACs to “refrain from negative attacks.” Asked where she stands on that this time around, Wu sidestepped the issue in a brief interview.

“We're going to stay focused on making sure Boston is the positive example that the country needs right now,” she said.

Cunningham, an expert in dark-money politics, contrasted this Boston election to 2013, when Marty Walsh faced John Connolly; both stayed away from personal attacks. Connolly even called Walsh a “good man” until the very end. And in 2021, the race between Wu and her challenger Annissa Essaibi George remained relatively civil until the final months, when clashes flared up during debates — particularly around how to handle a homeless encampment and drug use by Melnea Cass Boulevard.

Super PACs played a fairly prominent role in both of those elections, Cunningham said. But the sheer amount of money flowing into the 2025 election through big money groups is having an outsized impact, he said. And in his view, that’s not good for voters.

“Super PACs, no matter what, to my mind are a curse on Democracy,” Cunningham said. “Because it enables your people to spend wildly, independently of the candidate, where the candidate can say, ‘Oh, I'm not responsible for that.’”

The two other Boston mayoral candidates, Domingos DaRosa and Robert Cappucci, have no Super PAC backing, according to public campaign records, and no attack ads.

On Monday, Cappucci told WBUR he has put roughly $10,500 of his own money into his campaign so far this year that will be reflected in public filings by the end of the month. DaRosa has $1,849 in his campaign account, and said he’ll add another $2,200 in the next few days.

As he’s watched millions pour into the race, DaRosa, a Hyde Park resident and longtime community organizer, said he’s struck by how little of it will go towards “real life issues,” and how deeply the flood of money has impacted his campaign’s viability.

“Because I’m not raising $100 million,” he said, “I’m not a credible candidate? But I’m doing the work.”

With reporting by WBUR's Andrea Perdomo-Hernandez.