"It has been the honor of my life to serve the people of Maine in the United States Senate," Collins said. "I'm proud of all I have been able to accomplish for our state and for our country in the past 30 years." She was first elected in 1996 and had won five straight races, several of them after trailing in polls. Democrats needed a net gain of four seats to take the chamber, and Maine was one of them.

Collins was the only Republican in Congress from New England and the only Republican incumbent running in a state Kamala Harris won in 2024. Maine has voted for the Democratic presidential candidate in every election since 1992. Collins had survived that pull before, most recently six years ago against Sara Gideon, by running a hyperlocal campaign that kept President Trump at a distance and stressed her role in the Senate and as head of the Appropriations Committee. She ran the same race this time.

Jackson, 58, is a fifth-generation logger and a former president of the Maine state Senate. He was not the party's first choice. Governor Janet Mills, 78, was recruited early but dropped out for lack of funds. Graham Platner then became the presumptive nominee until he withdrew in July after a sexual assault allegation tied to a 2021 incident. Jackson was chosen at a hastily organized convention and entered the race in late July.

His campaign was populist and built around labor. He called Collins a "rubber stamp" for Trump and attacked her votes to confirm Justice Brett Kavanaugh and Health and Human Services Secretary Robert F. Kennedy Jr. His campaign said her Kavanaugh vote helped make possible the 2022 overturning of federal abortion rights. He urged voters to "stand up to Donald Trump" and "stand up for our democracy," and faulted Collins for not doing enough against the broader tariff regime, though she had publicly opposed Trump's tariffs on Canada. Collins, for her part, questioned how effective Jackson had been as a legislator.

The trade war shaped the final weeks. Maine imports $4.1 billion in goods from Canada each year, including $2 billion in heating oil and $263 million in electricity, and Mills has said the state's forest product exports to Canada have fallen 20 percent since the dispute began. In the campaign's last days, Collins announced the lifting of tariffs on nine categories of Canadian goods, while Trump imposed levies on dozens of new ones. Polling found about 60 percent of Maine voters disapproving of Trump, with higher energy prices and a sharp drop in Canadian tourism among the complaints. Gas and diesel prices, the war with Iran and a Republican-led Congress with a polarizing agenda added to the pressure on her.

Some voters stayed with Collins because of her record of winning federal backing for Maine's economy. Others, like retired military officer Michael Furrow and voter Dan O'Connell, voted for Jackson hoping for an end to the tariffs. Nearly $218 million was spent on advertising in the race, which was tight until mid-October before Jackson gained an edge.

Most final polls had him ahead by 5 to 9 points. One, from Emerson College, had Collins ahead by 1.2 points, within its margin of error. Jackson was trusted more on cost of living and on what is best for Mainers, while Collins led on immigration. Their net favorability ratings were close: minus 3 for Jackson and minus 1 for Collins.

Jackson described the mood on the trail this way: "There was a lot of anger about what's going on in this country. I felt that anger, too. But there was also so much joy ... joy because they know this government is broken and the only ones who are going to fix it is us."

After the election, Canadian Prime Minister Mark Carney said his country has begun "more intense" trade negotiations with the United States. He said progress has been made but a deal has not been finalized.