It’s heading toward the final election season stretch, and like clockwork the debate wars are underway.

“You can’t do the job if you don’t show up,” independent gubernatorial candidate Terry Hayes said in a recent release, castigating the party-backed candidates – Republican Shawn Moody and Democrat Janet Mills – for withdrawing from multiple proposed debates and forums in recent weeks.

On Monday, the other independent candidate – Alan Caron – said he knew of at least five proposed events for all four candidates that have been canceled in just the last week because a party-backed candidate refused to attend.

Next week the debate season will finally get underway in earnest, with the first of at least a half-dozen gubernatorial debates being held Oct. 3. at the Portland Regional Chamber of Commerce.

Debates can play an outsized role in a state with a diverse political makeup: In Maine, 33 percent of voters are registered as Democrats, 27 percent as Republicans, 35 percent as unenrolled, 4 percent as Greens and 0.5 percent as Libertarians, according to the most recent data.

“You have to do it,” said L. Sandy Maisel, a government professor at Colby College in Waterville. When candidates “are having difficulty getting any traction, you go where you can go where people can see you.”

Maine’s gubernatorial race has Mills and Moody virtually neck-and-neck, upping both the risk and reward factors for a debate.

Front-runners and party-backed candidates, who tend to lead the polls in the early stages of a campaign, have less to gain from a debate, which is mostly a way to introduce candidates and their issues to a broader audience. A gaffe – think of Al Gore’s sighs in the 2000 presidential debate, or Rick Perry forgetting which federal agency he wanted to cut in 2011 – can show up in an opponents’ campaign ad, or a carefully crafted message can go off track.

For independent candidates, who usually lag in fund-raising and media coverage, appearing on stage with the party-backed candidates can elevate their political status, result in tons of free advertising, open up fundraising channels and give them the chance to go head-to-head rhetorically with the other candidates on policy issues.

Four years ago, independent candidate Eliot Cutler railed for more gubernatorial debates with Gov. Paul LePage and Mike Michaud, certain it would elevate popular support for his campaign.

The same dynamic is playing out in the campaign to unseat Sen. Angus King, with long shot party-backed challengers calling for more debates against the independent incumbent. In August, at a Portland debate on gun rights organized by students, the challengers hammered King for not attending the debate – one employing a person in a chicken suit to walk about Portland, and leaving an empty chair at the debate to emphasize King’s absence. King has been unmoved.

The events that begin next week are all scheduled to have all four gubernatorial candidates attend, and to be in a debate format where the candidates can react and respond to the others, compared to the more plentiful forums, in which candidates all speak on certain, usually prearranged, questions.

Forums are often sponsored by issue-oriented organizations, such as educational, business or industry-specific entities like tourism, wood products or healthcare.

More debates were proposed, but Moody said he could not attend. Once one party-backed candidate drops out, it usually prompts the other party-backed candidate to also withdraw, and the debate fizzles out.

In the U.S. Senate race, a spokesman for Republican challenger Eric Brakey said the campaign would have liked four or five debates with King – yet they’ve only lined up two, both in the last week of the campaign.

“We’re just disappointed that we’re going to have an hour or two to discuss the last six years (of King as a U.S. Senator) and to talk about another six years,” David Boyer said. “It doesn’t seem right to just have an hour or two for that.”

Campaign veteran David Farmer said candidates must go into debates with a clear idea of what they want to accomplish, and mindful that the stakes are high.

“Even in hyper-partisan times, there are still persuadable voters, swing voters,” said Farmer, a veteran Democratic campaign consultant who is not currently involved in any gubernatorial campaign. “It’s a mistake to underestimate the debate and the (impact) the coverage of a debate can have.”

There is a question about how much a debate can influence voters.

Political scientists have analyzed the impact of presidential debates on polling and consistently found that debates don’t really move the needle more than a few points. The reason? People watching the debates may learn new information or get a “feel” for the candidates, but most have already made up their minds – particularly since most debates occur late in the campaign after most voters have reached a decision. Viewers, both in the audience and following media coverage later, tend to be people who are already interested in politics and are mostly party loyalists.

Maisel, the Colby professor, said candidates make tactical decisions about which forums and debates to attend: Candidates are more likely to attend forums and debates held by groups aligned with their ideology – or sit out events that might prove less friendly. With limited time and resources, candidates will put their energy into the most effective use of their time, which might mean missing a debate to hold a meeting with a group that might be swayed.

Debates are also high-stakes events, Farmer said.

“Even with experienced leaders, there are very few times you are in a debate setting,” he said, noting the need for candidates to prepare carefully for a debate. “It’s live TV, live radio – this is something you don’t do in the normal course of your life, even if you are speaker of the House. We don’t have the opportunity to speak to large audiences or spend an hour and half in rhetorical combat.”