By Jaime Suarez, Belmont Voice correspondent
As the 2026 midterm elections approach, redistricting conflicts are playing out across the country. An April 2026 U.S. Supreme Court ruling in Louisiana v. Callais weakened the Voting Rights Act of 1965, prompting states such as Florida and Tennessee to redraw their maps. Texas and California redrew their maps before the Supreme Court issued its ruling.
Massachusetts, however, has kept its voting districts.
The state has faced few legal redistricting challenges. In 2021, lawmakers created minority seats that did not shift the partisan balance, a move that state Democratic Sen. William Brownsberger, co-chair of the Special Joint Committee on Redistricting in 2021, said reflected the Senate’s redistricting priorities. He said these changes show up in the elections and help the state accurately represent its citizens.
What is Redistricting?
Redistricting is the often politicized process of legally redrawing a state’s electoral map, according to the Redistricting Data Hub, an online database that provides data for “nonpartisan map drawing and analysis.” Redistricting happens at both the federal and state levels, from the House of Representatives to state legislatures and even school districts. Candidates campaign in their respective districts to represent the communities within them.
State governments typically redraw their maps every decade using U.S. Census data. Mapmakers examine population totals in each district and move voting district boundaries to balance out the numbers. Officials try to avoid splitting neighborhoods between districts and sometimes reunite areas that were previously split.
Redistricting differs from gerrymandering, which happens when state politicians redraw maps for political gain. The American Civil Liberties Union describes the practice as “politicians picking their voters,” because it ignores Census data and crafts districts that will keep the sitting government in power.
Kosuke Imai, a professor of government and statistics at Harvard University, said in an article from Paul Massari that “Gerrymandering reduces electoral competition.”
“We observed that the number of safe districts has increased dramatically over the last 10 to 20 years as political geography has become more polarized— by around 25%,” he said.
Arjun Vishwanath, a political science professor at Boston University, said safe districts are not necessarily a bad thing.
“If every district was designed to be a toss-up, say a 50/50 split between Democrats and Republicans, then one party would win every seat if there was a national swing,” he said. “That system is over responsive.”
Redistricting in Massachusetts
Massachusetts last redistricted in 2021. Brownsberger co-chaired the redistricting committee with state Rep. Michael Moran, D-Boston, and then-Gov. Charlie Baker signed the maps.
The redistricting happened during the COVID-19 pandemic, which saw the population of Western Massachusetts shrink and that of cities grow. The committee enlarged the western districts and shrank some city districts, such as Brownsberger’s Suffolk-Middlesex District (Belmont, Watertown, Cambridge, Allston-Brighton).
The map altered Brownsberger’s district in three ways. It united Allston-Brighton inside the district, moved the South End, Back Bay, and some of the East Fens neighborhood to the 25th District, and added most of West Cambridge, which borders Watertown and Belmont.
“You want to keep towns whole, and you don’t want to scramble across town boundaries,” Brownsberger said.
He also said the peculiar shapes of districts in the Boston area stem from the city’s “funny shape,” which preserves historical lines. Keeping communities together reduced the number of towns split between districts from 21 to 11, he said.
“People have an identity within the district. They’re used to voting together,” Brownsberger said. “There are political structures like town committees. The [representative] has a relationship with a bunch of people. You don’t just scramble that every 10 years for the heck of it.”
Given current political sensibilities, could Massachusetts ever draw a Republican congressional district? Brownsberger said no. Massachusetts leans heavily Democratic, even though many Republicans have often held the governor’s office, including presidential candidate Mitt Romney and Baker, now the president of the NCAA. However, Democrats are spread so evenly throughout the state that it is mathematically impossible to draw up a Republican seat for Congress.
He cited a 2019 paper by a former associate math professor at Tufts University, Moon Dunchin, titled: “Locating the Representational Baseline: Republicans in Massachusetts.”
“This is the bottom line,” Brownsberger said of the paper’s main findings. “In several elections studied, researchers wrote: ‘Though there are more ways of building a valid district plan than there are particles in the galaxy, every single one of them would produce a 9-0 Democratic delegation.”
There is no way to redraw the existing boundaries to favor one party or another, at least at the Congressional level, because there is no flippable seat. BU’s Vishwanath believes the Senate did not try hard enough to create more competitive districts.
“If they wanted, they could draw seats in which Republicans would be competitive,” he said. “Bristol County is quite competitive, and much of the exurbs of Worcester lean red too.”
Redistricting as an Equity Issue
During the redistricting, the committee did not just focus on unifying towns and adjusting for population changes. It tried to give minority voters a chance to elect candidates of their choice. Brownsberger said the committee combed through every district, identified the minority communities, and compared their voting tendencies with those of nearby communities. When communities voted cohesively with minority groups, the committee assumed it was possible for a minority candidate to win.
The committee found two such places in Boston and Lawrence. It redrew the 2nd Suffolk District, represented by state Sen. Liz Miranda, and the 1st Essex District, represented by state Sen. Pavel Payano.
Lawrence elected its first Hispanic senator after the changes separated the city from Andover, a majority-white area, and paired it with Methuen and Haverhill, which have large Hispanic populations. Brownsberger said this was the committee’s most substantial change
“That was really needed representation. [Payano] was a really key person in the whole conversation about protecting immigrant rights,” Brownsberger said.
Those changes may attract criticisms of suppressing white voters in the state. Vishwanath said redistricting in Massachusetts and the gerrymandering attempts in states such as Tennessee and Florida were not apples-to-apples comparisons.
“White people in Massachusetts are Democrat-leaning, unlike in those states,” he said. “Swapping Andover for Methuen and Haverhill makes the district more Hispanic, but not more Democratic. That approach lets Democrats add minority voices without the partisan advantage in the Legislature.”
