One of the more telling moments in the two debates among the four candidates in Maine’s 2nd Congressional District came during the final question they faced.

Asked if they’d accept the outcome of the ranked-choice voting contest, three of the contenders said they would.

But U.S. Rep. Bruce Poliquin, a two-term Republican from Oakland, passed up the chance to rule out a possible legal challenge if he comes up short Nov. 6.

“I’m going to circle in ‘Bruce Poliquin’ – one and only vote – drop it in the box and go forward,” the incumbent said.

“I don’t think he answered the question,” said Democratic challenger Jared Golden of Lewiston.

With three recent polls indicating that Golden and Poliquin are locked in a dead heat in the hard-fought race to represent the sprawling district, it’s becoming ever more likely that neither of the front-runners will collect a majority of the votes cast.

FiveThirtyEight, for example, said that “Mainers who cast first-choice votes for third-party candidates will end up deciding whether Poliquin or Golden wins with their second-choice votes.”

In every other federal election in American history, the winner would be whoever got the most votes, regardless of whether the tally topped 50 percent of the ballots cast.

This time around, though, for the first time, ranked-choice voting might lead to a different outcome. Maine is the first state in the nation to adopt the new voting option, the result of a 2016 citizen referendum that voters backed again during the June 2018 primary.

In the most likely scenarios, the two independents in the race – Portland lawyer Tiffany Bond and Southwest Harbor educator Will Hoard – will trail the two major party candidates in the first round of counting.

If that happens – and recent polls put them far behind Poliquin and Golden – then the candidate with the fewest first-choice votes is eliminated. Voters who preferred the eliminated candidate then have their ballots added to the totals of their second-ranked candidates, and the ballots are retabulated. If still no one has more than 50 percent of the votes, then the second-round last-place candidate is eliminated and voters who preferred that candidate then have their ballots added to the totals of their second-ranked candidates.

At that point, the front-runner who has the most votes is declared the winner. And there is no guarantee that the victor will be the same person who led after the first round.

Given that both Bond and Hoar said they would personally pick Poliquin last, it is likely, but not certain, that most of the votes they receive would follow suit, which would have the effect of boosting Golden’s chances.

Golden, Bond and Hoar said that if ranked-choice voting leads to an outcome they don’t like – such as losing out in the second round – they will accept the decision made by voters.

But Poliquin has never made that assertion. His campaign ignored requests for comment on the issue Monday.

Instead, its spokesman, Brendan Conley, said only that Poliquin “cannot in good conscience support any of the other candidates in this race.”

Bond said she believes congressional hopefuls “have a responsibility to be clear” about their intentions and actions that relate to the job. Poliquin’s failure to say whether he will go along with the election results, she said, “is not being forthright with his constituents.”

At the debate in Presque Isle, Poliquin said he deserves to win re-election.

“I don’t think anyone else has the qualifications that I do,” he said as he refused to select his second choice from among the challengers.

Golden said Bond and Hoar are “both nice people” and he would pick one or the other second.

Bond said the best choice after her would be Golden or Hoar.

“I’m surprised Bruce doesn’t want me as his second choice,” she added, “since I’m not Jared.”

Hoar said he would select either Golden or Bond as his second pick.

If Poliquin ends up in first place after the first round with a plurality of the vote, but winds up losing when second-place votes are added in, he could challenge the count in federal court.

There are, after all, unresolved legal issues surrounding ranked-choice voting, given that it’s never been tested in federal court.

During discussions at the Maine Supreme Judicial Court last spring, for example, Justice Donald Alexander questioned whether the system that lets voters rank candidates could violate the “one man, one vote” principle, according to the Associated Press.

His colleagues suggested it was an issue for another time.

Jim Burke, a longtime lawyer who teaches at the University of Maine School of Law, said he’s not sure there’s a federal issue that Poliquin could rely on for a case. But, he added, “I don’t have a robe and a hammer.”

Burke said the Maine Supreme Judicial Court’s advisory opinion that made it impossible to use ranked-choice voting in state general election contests wouldn’t apply to Poliquin’s race because the U.S. Constitution doesn’t mention plurality voting the way Maine’s does.

The question of whether ranked-choice voting could be challenged, though, is increasingly important given that several polls show that although Poliquin might well win the first round of voting, he could perhaps lose in the second round.

In a New York Times/Siena College poll, Poliquin and Golden each had 41 percent of the total, with the independents collecting 3 percent. The rest were undecided.

In a Portland-based Pan Atlantic Research poll, Poliquin and Golden each racked up 37 percent of the vote with Bond at 6 percent and Hoar at 3 percent. The rest were undecided.

A third poll by Global Strategy Group, disclosed Monday by the Democratic-leaning End Citizens United, found Golden ahead by a 48-42 percent margin among voters with a preference. It also determined that the undecided voters – about one in 10 – are more Republican than the general electorate, which may mean they are more likely to vote Republican in the end.

In any case, it is possible that one of the candidates could pick up enough support by Election Day to win outright by snagging more than 50 percent of the vote.

But it appears more likely that both front-runners will fall short.

Bond urged everybody voting in the contest to take the time to rank their picks.

“You’d be foolish not to rank because you might end up with the other guy” rather than the one you prefer more, Bond said.