Markey defeats Moulton in Massachusetts Democratic Senate primary on September 1

Sen. Ed Markey defeated Rep. Seth Moulton in the Massachusetts Democratic Senate primary on September 1, 2026, according to NBC News. Markey was winning by nearly 50 percentage points with 2 percent of the expected vote reporting at the time of the projection.

The race centered on generational change and ideology. Markey, 80 and seeking a third six-year term after representing Massachusetts in Congress since the 1970s, faced a challenge from Moulton, 47, a Marine veteran who has served in Congress since 2014. In a state where the Democratic primary winner is expected to prevail in November's general election, the contest became a referendum on progressive credentials and legislative accomplishment.

Moulton built his campaign around criticism of the status quo. According to PBS NewsHour, he repeatedly argued that the Democratic Party is stuck in the "status quo" and questioned Markey's accomplishments during his time in office. "People ought to ask, what are you going to accomplish in the next six years that you haven't been able to accomplish in the last 50?" Moulton said, per PBS. In campaign ads, he framed the race as a choice between new energy and old methods. "Sen. Markey and I want the same things, but wanting isn't winning, and the old way isn't working," Moulton said in one spot, per NBC News, listing policies including taxing oligarchs, abolishing ICE, and passing healthcare for all.

Markey responded by attacking Moulton's record as insufficiently progressive. According to PBS NewsHour, Markey pointed to Moulton's more moderate positions to argue that it is Moulton, not the older incumbent, who is out of touch with Massachusetts voters. Markey touted his role as an author of the Green New Deal and called himself a vocal supporter of Medicare for All, per NBC News. At an election-eve rally, Markey said, "It's all about not just sending a Democrat to the Senate, it's sending a progressive Democrat to the Senate from Massachusetts so there can be someone that reflects your values every single day," describing the race as "a progressive final round," NBC News reported.

Markey drew endorsements from progressive leaders. According to NBC News, Sens. Bernie Sanders of Vermont and Elizabeth Warren of Massachusetts both appeared in an ad for the senator, and Rep. Alexandria Ocasio-Cortez of New York endorsed him. Moulton and his allies, however, spent more on advertising. Per NBC News citing AdImpact, Moulton and his allies spent 7.1 million dollars on ads while Markey and his allies spent 3.9 million dollars.

A key flashpoint in the campaign involved transgender athletes. Markey sharply criticized Moulton on the issue, saying at the election-eve rally that Moulton "threw trans kids under the bus" after the 2024 election, per NBC News. Moulton had told The New York Times after the presidential race: "I have two little girls. I don't want them getting run over on a playing field by a male or formerly male athlete, but as a Democrat I'm supposed to be afraid to say that," NBC News reported. In an August debate, Moulton apologized. "If you're in the trans community or you're a trans kid feeling the weight of the Trump administration and the Supreme Court, you matter. You're valued, and I will always have your back," he said, per PBS NewsHour.

Markey also attacked Moulton's healthcare positions. According to PBS NewsHour, Markey sharply criticized Moulton for opposing Medicare for All, though Moulton has called for universal healthcare. A group aligned with Markey, Commonwealth Together PAC, launched ads pointing to 2019 comments from Moulton's unsuccessful 2020 presidential campaign, saying Moulton opposed Medicare for All and taxing billionaires, per NBC News.

Markey is not the only incumbent in Massachusetts fending off a generational challenge. Rep. Stephen Lynch, 71, who has held the 8th District seat in south Boston since 2001, faces Roath, a 39-year-old lawyer who contended that it is time to end "wait-your-turn" politics, per PBS. Rep. Richard Neal, 77, first elected in 1988 and known as the dean of the New England House delegation, is challenged by progressive public school teacher Jeromie Whalen, 39, in the 1st Congressional District of western Massachusetts, per PBS.

Markey has defended incumbency on the grounds of experience. At a rally on the eve of the primary, Markey said, "It's all about not just sending a Democrat to the Senate, it's sending a progressive Democrat to the Senate from Massachusetts so there can be someone that reflects your values every single day," and described the race as "a progressive final round," per NBC News. He also vowed to continue fighting President Donald Trump. "It's a moment in history where Trump is challenging everything that started right here 250 years ago. We have a message from Massachusetts: We are going to fight," he said in one ad, per NBC News.

Markey has navigated a similar challenge before. According to PBS NewsHour, Markey notably fended off a challenge in 2020 from Rep. Joe Kennedy III, a younger rival from one of the nation's most famous political families. Markey fended off that challenge by aligning himself with the liberal wing of the Democratic Party, per PBS.

Markey was first elected to the Senate in 2013 after serving nearly 40 years in the House, per NBC News. Moulton enlisted in the Marines after the attacks on September 11, 2001, and served four tours of duty in Iraq, per PBS NewsHour.