With the election only days away, four candidates in a hotly contested race to become Portland’s next mayor are intensifying their voter outreach as they look to get their supporters out to the polls.

This is the third – and costliest – mayoral contest since voters changed the position in 2010 from a part-time ceremonial mayor chosen by city councilors for a one-year term to a full-time position with a four-year term elected by voters citywide.

Mayor Ethan Strimling is being challenged by City Councilor Spencer Thibodeau, former school board chair Kathleen Snyder and restaurant waiter Travis Curran.

The Portland mayoral election is Maine’s only ranked-choice municipal election and voters on Tuesday will be able to rank their candidates in order of preference. If no candidate secures an outright majority on the first count, the second choice votes of the last place candidate will be allocated. And that process, known as an instant runoff, will continue until a candidate receives more than 50 percent of the vote.

The unpredictability of the four-way race had all of the candidates sounding optimistic about their chances on Friday. In the waning days of a long campaign, most candidates said they are spending heavily on voter outreach, including direct mail, text messages and TV ads, while also relying on armies of volunteers to canvass the city in hopes of turning out the vote.

Strimling, 52, said he expects to have 100 volunteers canvassing this weekend with the goal of knocking on 8,000 doors. His last campaign finance report, required for expenditures over $1,000 within the last 11 days of the campaign, was filed Oct. 25 and shows $31,300 spent on direct mail.

“It’s exciting,” Strimling said. “It’s been very competitive and I feel like it’s been a great opportunity to talk about what we have accomplished. I feel like it’s clear to voters what the choice is.”

Both Thibodeau and Snyder said they have tried to run positive campaigns, amid what they described is negative campaigning by the incumbent and his allies through fundraising emails and mailers. However, Strimling has also been attacked by the political action group Unite Portland, which was formed specifically to oppose his re-election but not to support any other candidates.

Clockwise from top left, Travis Curran, Kate Snyder, Spencer Thibodeau and Ethan Strimling are the candidates in the race for Portland mayor.

Thibodeau has filed a second 24-hour finance report showing $2,500 paid to Chann Creative for campaign consulting and nearly $7,800 to Mach3Media for direct mail. He expects to file another finance report Monday, he said.

“We feel cautiously optimistic, but we continue to work to reach every voter we can,” Thibodeau said. “The response has been unequivocal that people want and desire a new mayor. Our message of affordable housing and workforce housing and sustainable growth and good government is resonating with voters.”

Snyder said she is “energized” in the final days of the campaign and focused on executing a voter turnout strategy. She said over 40 volunteers will be going door-to-door and text messages will be sent to supporters.

Snyder has filed two 24-hour reports showing $5,000 for online advertising, $3,000 to Sylvan Strategies for campaign consulting, $8,500 for mailers and $5,000 for TV ads.

“At this moment, I feel really energized by the whole thing,” Snyder said. “I have run the race I intended to run, one truly based in the community and focused on staying positive.”

Both Snyder and Thibodeau have booked airtime for TV commercials. Thibodeau booked 15 spots on News Center Maine (WCSH/WLBZ) last week through Election Day. And Snyder has booked 10 spots on News Center Maine and six spots on WGME.

In 2015, both Strimling and incumbent Michael Brennan ran TV ads as well.

Curran, who has no political experience, said he will be working his regular shifts at Empire Chinese Kitchen this weekend and campaigning when he can. Last week, he held several meet-and-greet events downtown that allowed him to reach more voters, but he conceded that a lack of fundraising has limited his ability to reach voters.

“My name has been spread around the restaurant industry and hopefully they show up on Tuesday,” Curran said.

Despite being out-organized and outspent by more experienced political rivals, Curran said he’s hopeful about his chances, since the winner is being selected by ranked choice voting – a method that allows people to cast ballots for long-shot or underdog candidates without feeling like they’re wasting a vote.

“It’s been invigorating and really powerful for me to see what I am capable of myself, without all of that big money,” said Curran, who vowed to remain politically active regardless of who wins Tuesday. “I’m not going to stop – win, lose or draw. There’s a fire in me now that I can’t put out.”

According to their financial filings, Strimling had raised over $160,000 in his quest for re-election, while Thibodeau has raised $110,000. Snyder has raised $85,000 and Curran has said he’s not actively fundraising. The totals shatter previous spending records in Portland, which created the unusual role of a full-time mayor with no executive duties.

Strimling, who has won the support of labor unions, progressive activists and immigrant associations, has clashed publicly with City Manager Jon Jennings and his council colleagues during his first term, and says he would continue to be an activist mayor when needed to enact policies that he believes in.

Snyder and Thibodeau have compiled endorsements of other elected officials and argued that the division during Strimling’s tenure has stalled progress on issues such as affordable housing. Thibodeau has said his experience on the council makes him best prepared to collaborate, while Snyder has emphasized her leadership of the school board during difficult financial times.

Curran, who has not raised campaign funds or compiled endorsements, has campaigned as the voice of artists and workers in the service industry who fear they’re being priced out of the city.

Portland’s mayor is currently paid $76,615 a year. The mayor’s limited official duties include chairing City Council meetings, working with city councilors and the city manager to establish and implement citywide goals, providing comments on city budgets, delivering an annual “State of the City” address and advocating for the city at the state and federal levels. The mayor has the power to veto any budget passed by the council, which in turn has the power to override it. All of the executive duties remain with the city manager.

While the full-time presence and city-wide constituency give the mayor the opportunity to develop policy and build support, the mayor is just one of nine votes on the City Council. Three city councilors also are elected by voters citywide, rather than only in a single district.