Stephen Lynch

U.S. Rep. Stephen Lynch is on track to return to Congress for a 14th term after defeating challenger Patrick Roath in a tightly contested Democratic primary in the state’s 8th Congressional District.

The 71-year-old South Boston congressman, who won his seat 25 years ago, overcame criticism from Roath, a progressive Jamaica Plain lawyer and voting rights advocate, that he had lost touch with his constituents in a changing district.

Tuesday night’s initial results made clear that Roath, 39, failed to convince enough voters that the district needed fresh leadership. He trailed Lynch 56% to 44% with nearly all ballots counted.

Roath won in Boston, where more than a quarter of the district’s voters live, by a 12-point margin.

But that lead disappeared in the district’s next four largest communities — Quincy, Weymouth, Brockton and Braintree — where the total votes exceeded the number from Boston. In those cities, Lynch won by a 25-point margin.

More than half the district’s votes came from those five cities. Taken together, Lynch won them 54% to 46%.

In the rest of the district, Lynch’s margin only improved.

He won the next three largest communities — Dedham with 53% of the vote, Canton with 62%, and Norwood with 58%.

Roath captured Hingham and Westwood. Lynch took the rest.

Still, Roath performed 10 percentage points better than Lynch’s last primary challenger in 2020, and 21 points better than his challenger in 2018.

Tuesday was a difficult night for a slate of hopeful underdogs challenging the veterans of Massachusetts’ congressional delegation.

Like Lynch, U.S. Rep. Richard Neal, in Congress since 1989, fended off a challenge from a more progressive candidate in the state’s First District. Neal won 54% to 46%, according to unofficial tallies around noon Wednesday.

U.S. Rep. Seth Moulton had turned his challenge of U.S. Sen. Ed Markey, an elected official for 50 years, into a referendum on Markey’s age. After turning 80 last month, Markey routed Moulton by 30 percentage points on Tuesday.

In a victory speech at The Playwright, a bar in his native South Boston, Lynch cast his campaign as a fight for working residents in increasingly pricey Greater Boston and as a charge to oppose the agenda of President Donald Trump.

Lynch, a former ironworker, said he knew what it meant to live paycheck to paycheck, and that “there aren’t many people in the United States Congress who have actually strapped on a pair of work boots for 20 years.”

At a pub across town in Jamaica Plain, Roath acknowledged in a concession speech that Tuesday’s results were disappointing. He called on his voters to back Lynch in the general election.

“We unfortunately are not getting the result that we were hoping to see tonight,” he told supporters at the Jeanie Johnston Pub. “I am deeply sorry about that, to all the supporters who are here, who are across this district, who are hoping for change and are not getting that this evening. But look, that does not minimize what we have done. We have shown that change is possible. We have made a start at that change.”

For Lynch, the win was an object lesson in sticking to the fundamentals, one veteran analyst suggested.

“Lynch was late to engage in that race. So incumbents, at some point, at a certain age tend to think they don’t need to engage an opponent and not give them oxygen,” Democratic consultant Mary Anne Marsh, of Boston, said. “And that was true in both Lynch and Neal’s case. And when they did (engage), it was obviously effective and they won easily.”