An 80-year-old progressive who’s been in Congress for nearly five decades won a key Senate primary by demanding “Medicare for All” and embracing transgender rights.

A pair of septuagenarian House Democrats turned back younger, more liberal challengers by highlighting the benefits of seniority and their skill at bringing federal funding home to their districts.

And an establishment-linked candidate won an open House seat on his second try, bolstered by endorsements from former President Joe Biden and former Vice President Kamala Harris.

In other words, the results of Tuesday’s Democratic primaries in Massachusetts were a mixed bag, with signs for optimism for candidates across the generational and ideological spectrum.

“The assignment is to take back the House and the Senate and have it filled with fighters who are going to stop Donald Trump,’’ said Mary Anne Marsh, a Boston-based Democratic strategist. “That’s it. … There’s no other common denominator.”

Sen. Edward J. Markey was among the big winners Tuesday, scoring a decisive 30-point win over a more moderate rival, Rep. Seth Moulton, whose campaign was built on a call for generational change.

But the topic of age, said Marsh, “became a media narrative, but it’s not the voters’ narrative.” 

Usamah Andrabi, a spokesperson for progressive group Justice Democrats, also cautioned that age alone should not become shorthand for defining Democratic divisions and disappointments. 

“It’s never been about just older versus younger candidates. If that was the case, the most popular politician in our party wouldn’t be an octogenarian talking about oligarchy across the country,’’ he said, referring to Vermont Sen. Bernie Sanders. 

“Voters are not looking to replace their old corporate shills with young corporate shills. They’re looking to replace their corporate shills with fighters for the working class,” he added. 

A push against the gerontocracy in Washington has surged through Democratic politics this year, as the party continues to grapple with the fallout from Biden’s ill-fated 2024 reelection campaign. Among the seven House Democrats who lost their bids for renomination this year, most were felled by younger opponents running to their left. 

Progressives say “the age issue” is just one calculation Democratic voters are making. 

“It’s certainly a component, but as Sen. Markey’s overwhelming victory last night proves, people are voting based on support of a progressive agenda,’’ said Robert Dempsey, political director for Our Revolution, the Sanders-founded progressive group that endorsed Markey.

Wins for the establishment

Two Our Revolution-backed candidates fell short in their quest to topple long-time incumbents in Massachusetts. 

In the 8th District, Rep. Stephen F. Lynch, 71, staved off challenger Patrick Roath, a 39-year-old lawyer and voting rights activist from Jamaica Plain, winning by 11 points, according to The Associated Press. 

Lynch, a former union ironworker who was first elected to the House in 2001, contrasted his working-class roots and deep ties to the district with Roath’s background as a corporate lawyer who was raised in Connecticut. 

“There was a lot of money spent against Stephen Lynch and a lot of advertising saying that he was MAGA’s favorite Democrat, and clearly that just didn’t work,’’ longtime Lynch adviser Scott Ferson told Liam Kerr, co-founder of the centrist group Welcome PAC, on a livestream Tuesday. “Voters are pretty grounded in Massachusetts, and if you give them … an authentic take on where things are, they’ll vote for you.”

Across the state in the 1st District, Rep. Richard E. Neal, 77, defeated 39-year-old teacher and first-time candidate Jeromie Whalen of South Hadley. But Neal’s single-digit winning margin was closer than expected, considering his towering fundraising advantage. In fact, the result appears to be the closest primary race of Neal’s near-four-decade congressional career. 

Dempsey said the relative closeness of the race signifies a hunger for change. 

“It’s proof positive that people are voting on our issues,’’ he said. “Maybe not enough to carry them to victory this time, but laying the groundwork for future victories.” 

As the top Democrat on the powerful Ways and Means Committee, Neal emphasized the millions of dollars he’s brought back to the district as he campaigned for a 20th term. He also significantly outraised Whalen, whose grassroots campaign — run from his canary-yellow Toyota cargo van — highlighted Neal’s support from corporate PACs and wealthy donors.

“’There is not a family in Western or Central Massachusetts that has not benefited from my work or been impacted by my influence in Congress,’’ Neal told supporters at his victory party in Springfield on Tuesday night.

In another win for the Democratic establishment, former Biden White House adviser Dan Koh prevailed in the primary for Moulton’s 6th District seat on the state’s North Shore. He beat a crowded field of rivals, including state Rep. Tram Nguyen, who had the endorsement of progressive Rep. Ayanna S. Pressley.

On the horizon

In weathering their primary challenges, Neal and Lynch did what fellow septuagenarian Rep. John B. Larson, whose central Connecticut district borders Neal’s, could not last month.

The 78-year-old was the seventh and most recent House Democrat to lose a  primary challenge this year, falling to former Hartford Mayor Luke Bronin, 47. Larson, a lunch-bucket Democrat who grew up in public housing, sought to run to the left of Bronin, whose pitch also centered on generational change. 

Other longtime Democratic House incumbents were felled by democratic socialists in New York, Michigan and Colorado. But more moderate members prevailed over progressive challengers in states such as Hawaii and North Carolina.

Though primary season is nearing the end, older House Democrats aren’t done facing intraparty challenges this year. A blue-on-blue general election battle looms in California between longtime Rep. Doris Matsui and Sacramento City Councilmember Mai Vang, who has Justice Democrats’ endorsement. (Under the state’s all-party primary system, both candidates secured enough votes to make the November ballot.)

The race is marked by both generational and ideological divisions. Matsui is 81, and has held the Sacramento-area seat since 2005, succeeding her husband, Robert Matsui, who was first elected in 1978.

Andrabi, the Justice Democrats’ spokesperson, said Vang was “on track” to defeat Matsui “because she’s leading with that forward-thinking vision.” 

He also said it was time for Democrats to move on from a platform that presents them merely as fighters against Trump’s MAGA movement. 

“We’ve been a party against Donald Trump for the better part of a decade rather than for something,” he said. “The candidates we’ve run this cycle are winning because, for the first time in a long time, Democratic voters have leaders who are actually building … an affirmative vision.”