Rep. Seth Moulton (D-MA) announced on Wednesday that he plans to mount a challenge to Sen. Ed Markey (D-MA), grounding his campaign in an argument for generational change.

“I just don’t believe Sen. Markey should be running for another six-year term at 80 years old,” Moulton said in his Senate race announcement. “Even more, I don’t think someone who’s been in Congress for half a century is the right person to meet this moment and win the future. Sen. Markey is a good man, but it’s time for a new generation of leadership.”

But unlike many of the younger challengers taking on older Democratic incumbents in the current election cycle, Moulton, 46, is generally more moderate, including on foreign policy issues, than Markey, an outspoken progressive. While Moulton has been strongly critical of Israeli operations in Gaza, his record as a whole leans more pro-Israel than Markey’s.

Markey faced a similar challenge from former Rep. Joe Kennedy (D-MA) in 2020 — ahead of the current anti-gerontocracy push in parts of the Democratic Party. Young progressives rallied around Markey, who won the race by 10 points. In that campaign, Kennedy sounded more supportive of Israel than the senator he was attempting to unseat. 

A recent Fiscal Alliance Foundation poll of the Senate race found that 63% of Massachusetts voters think Markey should not run for another term. In that same survey, Moulton led Markey, 38-30% among Democratic primary voters.

Markey is a prominent progressive voice in the Senate and voted seven times in the last year in favor of resolutions led by Sen. Bernie Sanders (I-VT) to block various weapons transfers to Israel. He memorably faced boos at a pro-Israel rally just days after the Oct. 7, 2023, attacks when he called for de-escalation between Israel and Hamas.

He also joined a letter accusing Israel of violating U.S. arms sales conditions imposed by the Biden administration, and pushed to incorporate those conditions into the supplemental aid package for Israel and other allies.

Markey called the U.S. strike on Iran’s nuclear program “illegal and unconstitutional” and said the attack “holds dangers for all Americans.” 

“This attack may set back but will not stop Iran’s efforts to get a nuclear bomb. The regime can rebuild its program and will now be highly motivated to do so. A diplomatic solution remains the best way to permanently and verifiably prevent Iran from acquiring a nuclear weapon,” Markey continued. “Trump’s illegal actions raise the risk of escalation into a wider regional war with grave risks for U.S. troops and personnel and civilians in the region.”

During a committee markup of the Antisemitism Awareness Act earlier this year, Markey led an amendment opposing the revocations of visas, detentions and deportations of students and faculty based on “protected conduct under the First Amendment,” one of a series of amendments that helped torpedo the bill.

Markey appeared on the streaming show of Hasan Piker, a far-left commentator who has repeatedly faced criticism for antisemitic rhetoric and support for terrorism, during last year’s Democratic National Convention. 

While Moulton, a Marine veteran, has been critical of Israel’s war operations in Gaza and called for increased humanitarian aid, he has not backed congressional efforts to condition, withhold or end U.S. aid to Israel since Oct. 7. He voted — with most House lawmakers — in favor of supplemental aid to the Jewish state last year.

After a meeting in May 2024 with then-Israeli Ambassador to the U.S. Michael Herzog, Moulton said he opposed Israel’s plans to launch a full-scale invasion of the southern Gazan city of Rafah and backed President Joe Biden’s threat to withhold weapons if Israel proceeded with that operation. In 2019, prior to the recent war in Gaza, Moulton offered support for a bill that would have placed restrictions on the use of U.S. military aid to Israel.

In July 2025, Moulton said in a statement that it is “a moral imperative for the Netanyahu government to alleviate this suffering” in Gaza and that “Hamas bears primary responsibility, but Israel has the ability and the obligation to help.”

“I want Israel to succeed in defeating Hamas and bringing the hostages home. But that won’t happen if its policies undermine its own mission, and you cannot win a war against terror by allowing civilians to starve,” Moulton continued, citing his own experience serving in Iraq. He said he told the Israeli ambassador directly that “what’s happening in Gaza is unacceptable.”

Weeks after the Oct. 7 attacks, Moulton cautioned Israel against launching an operation in Gaza without a robust plan for what would come after the war.

Moulton voted against several Republican-led measures — which split the Democratic caucus — that would have tightened U.S. sanctions on Iran and limited presidential authority to waive such sanctions, as well as against sanctions on the International Criminal Court.

At the same time, he voted in favor of redesignating the Houthis as a Foreign Terrorist Organization, having previously led a letter to the Biden administration supporting such action, and was a lead co-sponsor of a bill to expand funding for a cooperative counter-tunneling program with Israel.

Moulton stopped short of the blanket condemnation that many Democrats expressed for the U.S. strikes on Iran, saying, “One of the reasons I was reticent to just immediately condemn the strikes is because anything that gets us back to the negotiating table is helpful — that’s where we need to be at the end of the day,” though he said he would not have voted to provide congressional approval for those strikes.

He subsequently accused administration officials of “outright lying about things that we just don’t know yet” for declaring shortly after the strikes that the U.S. had completely “obliterated” Iran’s key nuclear facilities.

On antisemitism, Moulton voted in favor of the Antisemitism Awareness Act, as well as for resolutions describing anti-Zionism as antisemitic, calling for college presidents to resign over their testimony to Congress on campus antisemitism and for a GOP-led resolution condemning the firebombing of a hostage advocacy rally in Boulder, Colo., which also praised Immigration and Customs Enforcement.

Shortly after the Oct. 7 attacks, when a coalition of Harvard University student groups issued a statement condemning and blaming Israel for the event, Moulton, a Harvard alumnus, said that he “cannot recall a moment when I’ve been more embarrassed by my alma mater” and later condemned then-Harvard President Claudine Gay’s comments at a House hearing on antisemitism.

Both Markey and Moulton have supported expanded funding for the Nonprofit Security Grant Program to help protect Jewish and other nonprofit institutions.