AUGUSTA — Less than four months before Maine voters head to the polls, Independent candidate Eliot Cutler faces fundraising challenges, an incumbent Republican governor with fiercely loyal supporters and Democrats determined not to repeat the mistakes that cost them the 2010 election.

But Cutler, a 67-year-old from Cape Elizabeth, says he’s confident that his campaign will gain momentum this fall the way it did when he nearly beat Gov. Paul LePage for the Blaine House four years ago.

“If you look back at Maine’s three-way races … you find that independents tend to come on really strong in the end,” said Cutler, who lost to LePage by just 10,000 votes. “And our expectation is that it’s going to happen this time.”

Cutler hopes to gain support from voters concerned about the direction of the state but uneasy about returning to Democratic rule under Mike Michaud. As in 2010, Cutler said he’s focused on “treating voters like adults” by not only releasing policy proposals, but telling voters how he plans to pay for them.

But political observers say that time is running out for Cutler to overcome his biggest hurdle in the race: convincing anti-LePage voters that he is the candidate who can beat the Republican governor.

“He really needs to start showing some improvements in the polls. And if he doesn’t, then it’s going to be a question of how much of his own money does he continue to want to throw into this,” said Mark Brewer, a political science professor at the University of Maine.

Cutler’s relative success in 2010 has been attributed to a variety of factors, including a last-minute endorsement from Independent Sen. Angus King and concern among liberal voters that Democrat Libby Mitchell couldn’t defeat LePage.

This time around, most pre-election polls show LePage and Michaud nearly tied, with Cutler trailing by roughly 20 percentage points. Cutler’s campaign says that it’s doing much better than it was at this time in 2010, but observers say that’s because he was a political unknown four years ago.

Cutler, an attorney who served as an adviser on energy policy to President Jimmy Carter, counters that polls in three-way races are historically unreliable and that his opponents have real vulnerabilities that will hurt them in the final months of the race.

“There is, out there, a huge ‘anybody but LePage’ group of voters,” he said. “There is a pretty significant, and I would say, growing — according to our data — group of ‘anyone but Michaud’ voters. I haven’t met an ‘anybody but Cutler’ voter in the state of Maine.”

Cutler has tried to appeal to progressive voters by attacking Michaud for past conservative votes on abortion and gay rights — viewpoints that Michaud, a Democratic congressman, says have evolved over the years.

But Maine’s Democratic coalition — still reeling from the party’s poor performance in the 2010 race — has rallied endorsements and money behind Michaud early in the race this time around. Maine Forward, a political action committee, recently announced a $2 million television advertisement campaign that will start after Labor Day.

“This coalition is committed to a comprehensive effort to help ensure that Mike Michaud replaces Paul LePage as governor,” Sean Sinclair, a consultant for the PAC, said in an email.

Cutler, who’s again largely self-financing his campaign, has been significantly out-fundraised by LePage and Michaud, but says he’s confident that he will have enough money to finish — and win — the campaign.