Incumbent Sen. Ed Markey, D-Mass., and Rep. Seth Moulton, D-Mass., faced off in their final debate Thursday in the Massachusetts Democratic Senate primary, with both candidates arguing they would best deliver on progressive priorities for the deep blue commonwealth.

The two candidates clashed on several hot-button issues during the debate, including transgender athletes participating in women's sports, U.S. Immigration and Customs Enforcement, term limits in Congress, and how to counter President Donald Trump's agenda heading into the fall election.

What the Right Is Saying

Conservative critics seized on the debate moments to attack Democratic Party positions. Republican National Committee communications highlighted Moulton's exchange with Markey over transgender athletes, where both candidates affirmed their support for biological males participating in female sports.

"Another Democrat senator says 'it is absolutely essential' that males should be able to play in female sports," posted Crime Prevention Research Center President John Lott on X. "Should women boxers, runners, and shot put throwers have to compete against me? Why do Democrats keep fighting on this hill?"

On immigration enforcement, Moulton took an aggressive stance, calling ICE "completely corrupt" and "staffed by thugs," while calling for prosecutions of agency personnel.

"I think a mistake that we made after the first Trump administration is not doing enough to hold them accountable," he said during the debate.

Moulton also broke with some Democratic colleagues, criticizing Senate Minority Leader Chuck Schumer's leadership. "The Democratic establishment, especially under Chuck Schumer, has not been effective at holding Trump accountable, has not been effective in winning majorities across the country, has not been effective at fundamentally defeating Trump and the MAGA Republicans," he said.

Moulton pointed to New York City Mayor Zohran Mamdani as an example of Democrats breaking from party establishment politics while focusing on affordability issues.

What the Left Is Saying

Progressive voices praised both candidates for their commitment to left-wing policies while noting key differences on tactics. Markey, who has served in Congress since 1976, defended his long tenure when asked about term limits, saying he remains energized and capable of serving another term.

"I think everyone watching this debate can see that I'm more energized than I've ever been before and in my life," the 80-year-old senator said during the exchange.

On immigration enforcement, Markey doubled down on his opposition to ICE from its creation. "Seeds of authoritarianism" were planted when Congress established the agency, he argued, calling for accountability measures against the Trump administration's immigration policies.

Markey also called for Trump's impeachment and accused the president of using the SAVE America Act to "steal" the upcoming election. "That's what the SAVE America Act is all about," he said. "It's all about stealing the election this fall."

When asked about the growing influence of Democratic Socialists of America, Markey pointed to young voter priorities as the party's path forward. "They support Medicare for all," he said. "They know the healthcare system in our country is a sick care system. They want it fixed. They want a Green New Deal."

What the Numbers Show

The debate highlighted shifting Democratic Party positions on several key issues. Both Markey and Moulton expressed support for allowing transgender athletes in women's sports, which represents a position that has evolved significantly within the party over the past decade.

Both candidates called for abolishing ICE, a position that was considered radical when first proposed in 2018 but has since gained broader acceptance among progressive Democrats. Massachusetts law currently allows transgender athletes to compete in female sports categories.

The SAVE America Act championed by Trump would require proof of U.S. citizenship to register to vote and photo identification to cast ballots in federal elections, measures that have faced intense Democratic opposition as having a disproportionate impact on minority and low-income voters.

Democratic Socialists of America has grown significantly since 2016, with DSA-backed candidates winning several primary victories ahead of midterm elections. The organization now claims tens of thousands of members nationwide.

The Bottom Line

The Massachusetts Senate debate showcased the intensifying competition within the Democratic Party between established incumbents and progressive challengers seeking to push the party further left.

Both Markey, a 48-year congressional veteran, and Moulton, a two-term representative with military experience, sought to position themselves as most committed to delivering on far-left agenda items while differing on tactical approaches to opposing Trump.

The debate's sharpest exchanges centered on cultural issues, particularly transgender athlete participation in women's sports, where both candidates aligned on the progressive position despite Moulton's previous expressed concerns about biological males competing against female athletes. That earlier comment by Moulton drew criticism from Markey during the debate, with the incumbent accusing his opponent of using transgender individuals as "political fodder."

Moulton apologized for past remarks while arguing Democrats must control internal debates rather than cede ground to Republicans on such issues.