Sen. Ed Markey and John Deaton square off in only debate before election

In three weeks, Democratic incumbent Sen. Ed Markey and Republican John Deaton will face off on ballots across the commonwealth. But first, the two Senate candidates met in an antagonistic debate Tuesday evening — the only scheduled debate between the two before the Nov. 3 election.

The debate, hosted by WBZ-TV’s John Keller, pitted longtime politician Markey, 80, against a relative political newcomer in 59-year-old Deaton. The Republican nominee first entered the Massachusetts political scene in 2024, when he challenged Sen. Elizabeth Warren and lost by a nearly 20-point margin.

Deaton, a lawyer who specializes in representing asbestos poisoning victims and advocates for cryptocurrency, ran unopposed in the Republican primary earlier this year. Markey defeated Rep. Seth Moulton by nearly 30 points in the Sept. 1 Democratic primary.

According to late September polling by UNH, Markey is favored to defeat Deaton by 23 points to win what would be his third full term as senator. If Deaton were to win, he would be just the second Republican senator from the state to win since 1966 and the first since Scott Brown in 2010.

Tuesday’s debate was headlined by Markey’s repeated attempts to cast Deaton as another GOP soldier for President Donald Trump’s agenda. The senator emphasized the importance of a Democratic majority in the Senate to place checks on the president.

Deaton subsequently distanced himself from the MAGA base and painted himself as a bipartisan politician throughout the debate. His attacks centered on the progressive senator’s “extreme” positions and shortcomings in delivering promises across 50 years in Congress.

Here are 5 takeaways from Tuesday’s debate:

A focus on Donald Trump

The candidates’ respective relationships to President Donald Trump proved to be the largest point of tension between the two.

Markey, who voted against 21 of Trump’s 22 cabinet appointees in 2025, positioned himself as a staunch opponent to the president during the debate. He strove to paint Deaton as nothing more than a cog to further Trump’s agenda.

Markey invoked the president’s name more than 40 times throughout the hour-long debate, including in the first sentence of his opening remarks.

“I’m going to Washington to be a check on Donald Trump. Mr. Deaton is going to Washington to be a blank check for Donald Trump,” Markey said in his opening statement.

In a state where UNH polling shows nearly three-quarters of residents disapprove of the president, Markey’s messaging aligns with residents ahead of the midterm.

Deaton tried to paint the senator as giving broken-record responses that failed to address the Republican as a candidate.

“You notice how many times he talks about Trump, Trump, Trump,” Deaton said during the debate. He later added, “Senator, my God, … I’m John Deaton, and I’m the one that is debating you, not Donald Trump.”

Deaton has made his self-described distance from Trump and the Republican MAGA base a key point in his campaign. During the debate, Deaton said he has never endorsed or voted for the president. Deaton differs from the MAGA base on several key policies, as a pro-abortion rights, anti-Iran war candidate.

A split on partisanship

Deaton has positioned himself as more of a bipartisan, independent candidate who would work with both sides of the aisle. But, he said, his opponent is a “partisan person,” who will not oppose anyone wearing a “Democrat jersey.”

“I wear an American jersey. I call President Trump out. I’ll call a Democrat president out. We’ve got to stop hating each other and dividing each other,” Deaton said.

At one point in the debate, Deaton said he wished Markey was more open to working with the other side — he pointed to New York City Mayor Zohran Mamdani’s relationship with the president.

“Mamdani calls Trump a fascist. He calls him a misogynist, a racist. But then he goes to Washington and works for New York City,” Deaton said. “Go to Washington and work for the people of Massachusetts, regardless if it’s Trump, regardless if it’s … AOC. I’ll do that.”

Markey said Deaton wants voters to believe in a “fantasy land,” where Republicans who buck the president’s agenda don’t face consequences from the MAGA base. He specifically pointed to Republican senators who opposed the president and either didn’t file for reelection or lost the following election, such as Thom Tillis and Bill Cassidy.

“Right out of Godfather Part One, [Trump] gives them each an offer they can’t refuse. If they don’t do what he wants, they’re out,” Markey said.

Markey characterized Deaton’s attempt to be both independent and a Republican as an “oxymoron.”

“The ‘R’ on your jersey, Mr. Deaton, will just stand for ‘rubber stamp’ if you go down there,” Markey said. “You will be in the majority, and Donald Trump and those Republicans will once again control every single committee.”

Career politicians and red herrings

In Deaton’s opening statement, he stressed that he isn’t running against the 80-year-old senator because of Markey’s age. However, he attacked various “regrets” throughout Markey’s 50-year career in Congress.

For example, he pointed to Markey’s support for a ban on abortion in the 1970s — a position Markey changed in 1983, according to The Boston Globe. He also pointed to Markey’s vote to authorize the Iraq war — a position the senator says he now regrets, according to WBUR.

“Senator Markey is just same old, same old, 53 years of trying to get it done. Never gets it done, even when his party’s in control,” Deaton said.

Markey brushed off the attacks as “red herrings” meant to take away from the issues at the center of the election, such as rising prices for gas, food, electricity, and healthcare.

“It’s all about Trump’s policies, which have had a severe adverse impact on ordinary families watching this debate tonight,” Markey said. “If all it is is a continuation of business as usual … then they’re going to continue to suffer the way they are right now.”

Healthcare, energy, and AI

When it came to policy debate between the two candidates, there was a surprising amount of overlap in their positions. However, the two often differed in the means to get to those ends.

Markey, a firm progressive, continued to push for Medicare for all throughout the debate. He cited a 2025 report by the Boston Public Health Commission which found a 23-year gap in life expectancy between Roxbury and Back Bay residents.

While Deaton said he supports more affordable health care, he called Markey’s position “extreme.” Deaton said he instead has a plan to break up the few “vertically integrated insurance companies” that control a majority of Americans’ healthcare.

Both candidates supported various kinds of clean energy solutions.

Markey said the Green New Deal, which he co-sponsored, led to 93 percent of electric generating capacity in the country coming from wind, solar, and battery storage — a finding reported by the U.S. Energy Information Administration in 2026.

Deaton said he supported a “multifaceted” approach to energy with a belief in solar and geothermal energy. He also emphasized his support for nuclear energy.

Both Markey and Deaton also supported safeguards around artificial intelligence.

Markey, who has introduced nearly a dozen bills to create safeguards around AI, was vehement about placing guardrails on the technology during the debate. He said AI regulations are currently handled by Silicon Valley billionaires and agreements between Trump and AI CEOs.

If reelected, Markey said a Democratic majority would call AI “bros” to testify in front of Congress and be held accountable.

Deaton acknowledged the potential advantages of AI, saying the technology could help end cancer or hunger, but he said he worries about elderly residents who can be “taken advantage of” by AI.

While Tuesday evening was the only scheduled debate between the two candidates, Deaton asked Markey for a second debate in western Massachusetts at the end of Tuesday’s debate.

“You’re a very good debater,” Deaton said. “Can we agree right now, Senator?”

Deaton held his hand out towards Markey, but the senator didn’t accept the invitation.

“We have seen the clear differences between us,” Markey said. “The people of Massachusetts right now have had more than enough information given to them so they can make a decision on election day.”