FARMINGTON, Maine—Sen. Susan Collins (R., Maine) joined community leaders for an upbeat ribbon-cutting event here to celebrate the opening of an emergency-operations center she helped fund through her powerful role in the Senate.

Down the street, demonstrators opposing her re-election and supporting her Democratic challenger, Troy Jackson, protested her vote to confirm Supreme Court Justice Brett Kavanaugh, Elon Musk’s funding of Republican causes and the high cost of fuel and goods. One demonstrator dressed up as Marie Antoinette.

Collins’s bid to win a sixth term in the Senate has led to one of the nation’s most competitive races in the November midterms. To win, she must navigate a polarized electorate in President Trump’s second term, anger over inflation and fallout from the Supreme Court’s 2022 decision overturning Roe v. Wade.

Protesters, including some opposed to Collins’s vote to confirm Supreme Court Justice Brett Kavanaugh, demonstrated Oct. 21 during her campaign swing through Lewiston.

Collins, asked about the tough political environment, described it as the most difficult of her career. The campaign has included accusations by both sides of wrongdoing, frequent protests and vandalism of one of her offices.

“I have had tough races always, but this is the first time where there have been nonstop lies about me and my record—character assassination,” Collins, 73 years old, told The Wall Street Journal during a session with reporters last week.

Collins has won tough races in the blue state before on her way to becoming the longest-serving Republican woman in Senate history. She has cultivated an image as a bipartisan legislator who has focused on constituent service and delivering hundreds of millions of dollars for Maine as the powerful chair of the Senate Appropriations Committee. She travels the state, showing up for ribbon-cuttings and talking with voters at fairs and storefronts, with many recalling meeting her before.

In 2024, Collins was re-elected by a comfortable margin—despite trailing in opinion polls for most of the race—as Trump was losing Maine by 9 percentage points. Polls are tight again this time.

Collins’s re-election prospects have been threatened by a series of obstacles, many imposed by Trump: He remains deeply unpopular in Maine, and Collins’s opponent, Jackson, a former state senator, constantly points to her votes siding with the president.

The Trump administration is in the middle of a trade war with Canada, Maine’s top trading partner. Fuel prices remain high, including the cost of home heating oil, which has nearly doubled in the past year, as Maine residents prepare for winter.

Republicans have a 53-47 majority in the Senate, but Democrats are looking to flip a number of states, including Maine, Texas, North Carolina and Ohio.

Collins frequently notes to reporters the times she has broken with President Trump, who is unpopular in Maine. ‘Soul of the Senate’A Collins victory would cement her status as a giant in American politics and a figure with a nearly unmatched ability to occupy the nation’s shrinking political center. If she loses, her defeat will show the electoral limits of centrist GOP candidates running away from Trump in blue-leaning states.

“You lose Susan Collins, you lose the soul of the Senate,” said former Sen. Joe Manchin of West Virginia, a Democrat-turned-Independent who campaigned alongside Collins last week at a New Balance factory in Norway, Maine.

During the spring, the Collins campaign had expected to face Graham Platner, a political newcomer who electrified crowds. His candidacy, however, was derailed by sexual-assault allegations that he denied, forcing Democrats to hold a special convention to pick Jackson, a former logger close to labor unions.

In interactions with reporters, Collins frequently notes the times she has broken with Trump and the steps she has taken to soften the blow of tariffs and fuel costs.

She describes herself as the leading opponent of the Canadian tariffs, pointing to exemptions she has helped win for cement and road salt. Last week, she secured exceptions for some products used in agriculture, a boon for the state’s blueberry, apple and potato farmers.

Collins campaigns Oct. 21 with another centrist, former West Virginia Sen. Joe Manchin, at a New Balance shoe factory in Norway, Maine.

She has spent much of the fall working with the Trump administration to release emergency stocks of home-heating oil. She also has clashed with White House budget chief Russ Vought over administration efforts to cut funding already signed into law.

Jackson has his own challenges. Collins has blamed state policies under Jackson for high electricity rates. And Republicans have aired ads criticizing Jackson’s receipt of tens of thousands of dollars in annual travel expenses after he bought a home in Augusta, the state capital, where the Maine legislature meets.

Collins has supported abortion rights and noted that Jackson sided with antiabortion legislators roughly a decade ago. Collins has repeatedly won re-election by carrying moderate women, helping her stem losses in Democratic-friendly coastal towns in southern Maine. But there have been signs that her vote to confirm Kavanaugh—and the high court’s ruling ending a constitutional right to an abortion—might have damaged her brand.

Collins’s Democratic challenger, Troy Jackson, often points to her votes siding with Trump.

“That’s what sealed the deal. I was never going to vote for her again,” said Devan Weber, 44, an elementary-school teacher from York in southern Maine. Weber, a Democrat, said she voted for Collins in four consecutive Senate elections, including in 2020.

Collins’s familiarity can also help. In September, when Jim Grattello spotted Collins at a business-themed event at a gravel-and-sand company in Naples, Maine, he reminded her that he had served as mayor of Biddeford. “We walked in a parade together 30 years ago,” Grattello, a Democrat, told the senator. He said he intends to vote for her.

During the campaign, Collins has also faced allegations that the Federal Bureau of Investigation reviewed her ties to a donor who was seeking federal contracts, a matter that was closed by the Justice Department under the Trump administration, according to a report by ProPublica.

Collins has called the allegations that she exchanged federal contracts for campaign donations “completely false” and a “partisan hit job.”Collins and Manchin at Simones' Hot Dog Stand, where they spoke with customers and people from the town. Home pelted with eggs Since Collins’s 2018 vote to confirm Kavanaugh, local police have conducted more than 500 checks of her home in Bangor, Maine, according to an August report in the Bangor Daily News. Her home was pelted with eggs in September and, later in the month, her Biddeford regional office was vandalized.

“This is the worst I’ve ever seen,” said state Sen. David Haggan, a Republican from Hampden who supports Collins. “It’s terrible to see these horrible, vicious attacks.”

When a protester interrupted the final televised Senate debate, Collins responded, “This is obviously one of Troy’s supporters,” prompting Jackson to reply, “Oh, shut up.”He added that he didn’t “know that kid.”Collins has since aired advertising publicizing the incident. [video] Jackson Criticizes Collins’s Voting Record During Maine Senate Debate Jackson’s campaign has criticized Collins and her allies for noting that Jackson is married to his second cousin. Jackson’s longtime partner, Lana Pelletier, wrote in an opinion article in the Bangor Daily News last week, “Our children have been dragged into this campaign. Our relationship has been mocked.”

Collins raised the relationship in an interview with Politico in September. A radio ad paid for by a super PAC supporting Senate Republicans featured a folksy tune that included the lyrics, “If he screws his own family, he’ll screw yours too.”Collins said she had “nothing to do with that ad,” which was funded by the Senate Leadership Fund PAC, and said it should be taken down.

The skirmish underscored the degree to which more than $230 million in advertising has blanketed the state since January, according to data maintained by AdImpact. Republican groups have spent more than $134 million to help Collins, AdImpact data show.

“Susan Collins is a very good campaigner—she should never be underestimated,” said Joe Baldacci, a Democratic state senator from Bangor. “She’s got all kinds of money, but I think people are fed up. It’s just a question of whether they’re going to blame her enough or not.”