Republican Sen. Susan Collins and her challenger, Democrat Troy Jackson, are locked in a tight race two months before a pivotal election, a CNN poll released Wednesday found.

Jackson, the former Maine Senate president and third-place finisher in the Democratic primary for governor, led Collins 48%-45% in the poll of 880 likely voters in Maine. The poll was conducted by the research firm SRSS from Aug. 31 through Sept. 6, and its margin of sampling error was plus or minus 3.7 percentage points, meaning there was no clear leader.

The race is likely to remain tight until Election Day, with only 4% of voters saying they haven’t yet chosen whom they’ll vote for.

Jackson’s campaign touted the three-point margin in a news release.

“The numbers are clear: Mainers are ready for a change and a senator who will actually show up and fight for them and that’s Troy Jackson,” campaign spokesperson Maggie Amjad said.

Meanwhile, Collins spokesperson Shawn Roderick said in a statement that Collins “will continue making her case directly to Maine voters based on her record of bipartisan, independent leadership and delivering results for our state.”

Voters were especially polarized on the five-term senator.

Of those who said they would be voting for Jackson, 71% said they would be doing so as a statement against Collins, rather than in favor of Jackson. And of those who said they were voting for Collins, almost three-fourths said they’d be doing so to support her, rather than to oppose Jackson.

Voters had stronger opinions on Collins — perhaps a reflection of the gap in recognition between Collins, who has served in the Senate since 1997, and Jackson, who dramatically jumped into the race in July after Graham Platner dropped out amid an allegation of sexual assault. (Platner has denied the allegation.)

Collins had 41% favorability among likely voters, and just over half said they had an unfavorable view of her. Only 7% said they had no opinion on her.

Jackson, meanwhile, is still establishing himself in the race, and there is still room for either side to define his candidacy. About 36% of voters said they had a favorable view of Jackson; 42% said they had an unfavorable view.

Nearly 20% said they had heard of Jackson, but had no opinion on him.

That’s significant, especially when compared to Jackson’s predecessor, Platner. About half of those polled in a New York Times/Press Herald/Siena poll from June said they had an unfavorable view of Platner — but essentially all had heard of him.

Jackson is viewed more as a candidate of change than Collins, the survey found. More than 40% of voters said Jackson would “change things a lot” if he were to win a term in the Senate, while only 14% said the same for Collins, who has campaigned on her consistency and record of delivering federal funds for Maine as chair of the Senate appropriations committee.

The leader of Collins’ party, President Donald Trump, remains very unpopular in Maine. About two-thirds of respondents to the CNN poll said they disapprove of the job Trump is doing in office.

And Trump’s unpopularity may be a crucial factor in deciding this race. Almost half of respondents said they would be casting their vote to send a message that they oppose Trump.

Collins has attempted to distance herself from the president, especially in the ongoing trade war with Canada. Collins has said the the back-and-forth tariffs will “lead to higher costs, risk and uncertainty for Maine businesses” and has urged the Trump administration to return to negotiations with Canada.

Notably, Collins was also absent when Vice President JD Vance came to Maine last month to campaign for former Gov. Paul LePage in his race for Maine’s 2nd Congressional District. Collins said she had a scheduling conflict.

The tariffs themselves are also incredibly unpopular in Maine, the poll found: about 70% of respondents said the taxes are bad for the state.

The economy and cost of living were voters’ top concerns heading into the midterms. Almost half of the respondents said that was the issue they would consider most in casting their vote. The next most common answer, the state of American democracy, came in at 27%.

The poll also asked voters whom they prefer between Democrat Hannah Pingree and Republican Bobby Charles in Maine’s gubernatorial race. Pingree was well in front, with 52% of respondents saying they plan to vote for her, and 39% saying they’d vote for Charles.

Independent candidate Rick Bennett was not included in the poll — about 5% said they planned to vote for neither Pingree nor Charles, and 4% said they didn’t know.