Of all the states once seen as clearly in Hillary Clinton’s column, a new survey identifies the one perhaps most likely to tip to Donald Trump — and that state is Maine.

A Colby College-Boston Globe poll released Tuesday shows the presidential race in Maine is now within the margin of error, with Clinton leading Trump, 42 percent to 39 percent.

Also significant: The poll of likely voters, conducted last week by SurveyUSA, showed only a small portion of respondents, 5 percent, remain undecided less than eight weeks before Election Day.

Trump’s ascendancy in Maine is largely due to his dominance in the vast northern sector of the state — but analysts say it’s also a reflection of how Maine, like many other parts of the country, has become geographically more polarized. Its northern reaches, mostly rural, tend to be far more conservative than the southern, populous part of the state.

“Mainers for the first time in a while have to pay attention to the statewide race for president,’’ said Dan Shea, a political science professor and director of the Goldfarb Center at Colby College. “The Clinton campaign can no longer take this state for granted.’’

Earlier polls of Maine showed Clinton with a larger lead over Trump — in the high single digits and beyond. And while other traditional Democratic strongholds in the presidential races, such as Pennsylvania and Michigan, have also shown narrowing poll margins, none of these states present a history-making opportunity for Trump like Maine.

The last time a Republican won in Maine was in 1988, when George H.W. Bush, a Kennebunkport vacationer who was vice president at the time, carried the Pine Tree State. But the race for president was somewhat close in 2000, when the Democratic nominee, Al Gore, carried the state by 5 percentage points. In 2012, President Obama won Maine by 15 percentage points.

Amy Walter, a national political analyst at the nonpartisan Cook Political Report, noted that, historically, the number of states in contention two months out typically narrows to just a handful of battlegrounds. But this time, she said, polls suggest the race is moving to unexpected places like Maine.

“The good news for Clinton is that even if the map expands to Maine, she can lose it and still have a path to victory,’’ Walter said.

State Senator Andre Cushing III, a Republican from Hampden,said Trump is giving voice to the economic anxieties of middle class Maine voters.

“While people here were looking for hope and change eight years ago they are now so frustrated that they want the deep, substantial change that Trump represents,’’ Cushing said. “I think voters are coming to the conclusion that while Trump is not the perfect option, he is the best option for them.’’

Maine doles out its four Electoral College votes in an unusual way, awarding two votes to the statewide winner and another for each of its two congressional districts. Trump’s campaign had hoped to pick off a single electoral vote in the more conservative, vast, and rural Second District — something that has never happened in Maine’s political history.

But the poll shows Trump’s dominance in the Second District — he leads Clinton by 10 points there — is boosting him statewide, as well. In the First Congressional District, which includes Portland and points south, Clinton has an 18-point lead, showing just how politically divided the state is geographically.

What’s more, politics are shifting in the state once known for electing moderate Republicans like Margaret Chase Smith, who served as a US senator. The state reelected its controversial and highly partisan GOP governor, Paul LePage, in 2014.

“If Paul LePage’s reelection wasn’t a wake-up call to Maine Democrats, this poll should be,’’ said Mike Cuzzi, a former Obama campaign staffer and Democratic political consultant based in Maine.

Forty percent of respondents said they had a favorable impression of LePage in the survey, conducted a week after he openly mulled resigning following an inflammatory, expletive-laden voice mail he left for a state lawmaker. LePage is an ardent Trump supporter.

“Democrats here in Maine have struggled to connect with the core of Trump and LePage voters, which is generally white, rural, working-class men,’’ Cuzzi said. “In more populated states, Democrats can overcompensate for that with diversity in cities, but if you struggle with that group in Maine, you have a real problem.’’

The poll bears out this gender divide: Trump has a 21 point lead among men statewide, while Clinton has 17 point lead among women in the state.

Also in the Colby College-Boston Globe survey of the presidential race, Libertarian nominee Gary Johnson had 9 percent, and Green Party nominee Jill Stein had 5 percent.

The poll of 779 likely voters statewide was conducted via automated phone calls and Web surveys from Sept. 4 through 10. It had a margin of error of 3.6 percentage points.

The Colby College-Globe poll yielded similar results to a Washington Post/Survey Monkey Internet poll of Maine registered voters released earlier this month. That survey showed Clinton leading Trump, 37 percent to 34 percent, with Johnson at 15 percent and Stein at 8 percent.

While Maine’s four electoral votes are in play, Clinton is making headway elsewhere on the Electoral College map. Democrats are running competitive campaigns in Arizona and Georgia, two populous states that go a long way to a candidate’s receiving the necessary 270 Electoral College votes. At the same time, polls show Trump running strong in smaller states, such as Iowa. The most recent surveys also show he could be competitive in New Hampshire.

In many ways, Maine is just following a national trend as the state becomes more politically polarized.

“It’s hard reading the polling data without coming to the conclusion that Maine politics echoes what’s happening across the nation,’’ Shea said.

James Pindell can be reached at james.pindell@globe.com. Follow him on Twitter @jamespindell.