Daniel Lander, a senior aide to Boston Mayor Michelle Wu, announced Monday he will challenge a powerful Democratic state senator in 2026, at a moment of escalating tension between Boston City Hall and the state Senate.
Lander plans to run in the Democratic primary against state Senator William Brownsberger, a nearly two-decade veteran of the state Legislature and a member of Senate leadership who represents Belmont, Watertown, and parts of Boston and Cambridge. Brownsberger has not faced a Democratic or Republican opponent in more than a decade.
Lander, a senior policy advisor to Wu in City Hall, said he is running because he believes the Legislature is not doing enough to address the region’s cost-of-living crisis.
“The state Senate is a problem,” Lander, 34, told the Globe. “I’ve seen good ideas go up to the state Senate year after year and get killed, in particular by my opponent, and I think we need urgent change to make Massachusetts more affordable.”
In particular, Lander pointed to Brownsberger’s opposition to a transfer fee on high-dollar real estate transactions, a measure Wu and her allies say is crucial for funding affordable housing in the city. Brownsberger has also opposed Wu’s plan to shift the city’s tax rates in an effort to spare homeowners huge spikes in their bills.
Brownsberger has argued Wu’s plan would “give an additional property tax break even to our wealthiest homeowners, while increasing the burden on struggling small business owners.” He has offered his own proposal to protect homeowners from increased tax bills, but it has not been approved by the Legislature. The average single-family homeowner in Boston is set to see a 13-percent year-over-year increase in their tax bills.
In a statement to the Globe, Brownsberger said, “I welcome the opportunity to engage with voters in an active campaign.”
“I am eager to talk about my commitment to service, my record of delivering major reforms, and the challenges and opportunities facing the Commonwealth,” he added.
Next year’s state Senate race will be Lander’s first time as a candidate, though he has worked on political campaigns in the past, including Wu’s 2021 mayoral campaign and Elizabeth Warren’s 2020 bid for president. Lander has also served as the chair of Boston’s Ward 21 Democratic Committee and led efforts on LGBTQ outreach for multiple campaigns.
At City Hall, he has worked on efforts ranging from business recruitment and housing affordability to the new program “Boston Family Days,” when local cultural institutions open their doors to city students and their families for free. Lander said he will resign his role with the city Jan. 9 to focus on campaigning.
The primary contest will also be Brownsberger’s first contested election in more than a decade: He has not faced a Democratic or Republican opponent for his seat in the Legislature since 2012, state records show. First elected to the Legislature in 2006, Brownsberger currently serves as Senate president pro tempore and a committee chairman. Since winning a special election for Senate in 2011, he has never faced a primary challenge for his seat in the Legislature.
A former prosecutor and defense attorney, Brownsberger has decades of experience in local elected office, including as a Belmont selectman and chair of the town’s Democratic committee.
Known as a policy wonk, he has helped lead the Legislature’s efforts on redistricting and the Census and been a fixture in Senate leadership. A Harvard graduate and a Belmont resident since 1992, Brownsberger is married and has three daughters.
Lander lives in Fenway with his husband. Also a Harvard graduate, he grew up in Cambridge and attends services at Beth El Temple Center in Belmont.
Given Lander’s close ties to the mayor, his bid may be seen as a shot across the bow from Wu. Lander said he hopes to “earn her support” over the course of the campaign. Wu has not ruled out getting involved in primary challenges to Democratic state senators who have opposed her agenda.
State Senator Nick Collins, a Democrat from South Boston who has sparred with Wu, has already drawn two primary challengers.
Lander’s Senate bid could be a test of Wu’s political influence beyond Boston city limits. While she won re-election in a landslide this year, key pieces of her agenda have been blocked at the State House by fellow Democrats, a source of evident frustration for the mayor.
Massachusetts’ legislative elections are among the least competitive in the country; intra-party challenges against established Democratic incumbents are rare here — and successful ones all but unheard of. Lander said he recognizes it’s a challenge to take on an established incumbent, but said he believes his message will resonate. Residents are frustrated that the Legislature has not done more to address affordability issues, he argued.
Lander cited the record number of ballot initiatives that could appear before voters next year — on questions including rent control and lowering taxes — as evidence of “the inaction and inertia of our State House” on cost-of-living issues.
Prospective candidates have until spring of 2026 to file paperwork with elections officials.
Emma Platoff can be reached at emma.platoff@globe.com. Follow her @emmaplatoff.