BANGOR, Maine — Voters made Maine the first state in the nation to adopt ranked-choice voting for gubernatorial, congressional and legislative races on Tuesday.

Proponents of Question 5 ran a $2 million campaign facing no organized opposition. They pitched the new voting method as a cure for the kinds of plurality elections that have decided nine out of the last 11 gubernatorial races, including Republican Paul LePage’s wins in 2010 and 2014.

However, it must now clear significant hurdles based on concerns, including from Maine Attorney General Janet Mills, that it doesn’t pass constitutional muster.

Kyle Bailey, who managed the ranked-choice voting campaign, said it will be presenting a plan for implementation in the coming days, but for now, it’s “celebrating a pretty historic win for the people of Maine.”

“Voters are feeling like they have to vote strategically for the lesser of two evils, and this system gives voters more choice and more voice,” Bailey said.

Ranked-choice voting would apply in races with three or more candidates. A winner is declared if a majority picks a candidate as their first choice. But if not, the candidate with the lowest share of first-place votes is eliminated and second-place votes for that candidate are reallocated, a process that will be repeated until a majority is won.

The movement for ranked-choice voting has bubbled in some of Maine’s more wonkish corners for years. A three-year study from the League of Women Voters of Maine endorsed it in 2011, and two years later, a bill from former state Sen. Dick Woodbury, I-Yarmouth, failed in the Legislature. He was one of the leaders of this campaign.

But it was the polarizing LePage who provided the petri dish: He won in 2010 with just 38 percent of votes in an election in which independent Eliot Cutler — who advocated for ranked-choice voting after the election — would likely have beaten him if voters could rank choices.

That election led many Maine progressives to plaster “61%” bumper stickers on their cars, a reference to the share of the population that didn’t vote for LePage. However, his Democratic predecessor, John Baldacci, never won a majority, either.

Two constitutional issues have been flagged by Secretary of State Matthew Dunlap and Mills, both Democrats. The law likely will prompt a legal challenge, requiring an uphill two-thirds vote in the Legislature to refer a constitutional amendment to voters or call a convention.

Early in Maine’s history, the state employed a runoff process of sorts, but the state constitution was changed after one such election nearly resulted in civil war.

In 1880, Republican gubernatorial candidate Daniel Davis finished first, but he narrowly missed a majority. Back then, the Legislature had the power to pick the governor when no candidate had a majority. The House would pick two candidates from the top four finishers in the gubernatorial race, and then the Senate would pick the governor from those two.

So, incumbent Democratic Gov. Alonzo Garcelon, who had finished third in the race, tried to manipulate the process by alleging voter fraud and persuading officials to invalidate ballots to gain seats favorable to him in the Legislature.

Republicans won a court challenge, but Garcelon ignored an order, so Republicans gathered troops in Augusta. Civil War Gen. Joshua Chamberlain, a former Republican governor who led Maine’s militia, broke up the insurrection under threats of death and 12 tense days, after which Davis was seated.

Later, Maine voters allowed the governor to be selected by a plurality of votes, which they already had adopted in 1875 for members of the Legislature.

The Constitution also says that ballots must be received, sorted and counted by cities and towns, but ranked-choice tallying would have to be done in the secretary of state’s office.

If it becomes law, the new method’s impact on some of Maine’s elections could be far-reaching: Cutler likely would have beaten LePage in 2010 if voters could rank choices, though LePage would have been favored in 2014, according to a Bangor Daily News simulation.

It also would add complications to the voting process, though the majority of races likely would be won in the first round and voters likely would adjust to the system over time.

Political science research in San Francisco showed that it depressed turnout in elections there and ballot exhaustion — where voters don’t rank all available choices or mistakenly rank one candidate twice — is also an issue.

Portland began using the system in mayoral races in 2011, when 15 candidates ran. Michael Brennan won with 46 percent of all ballots, with nearly 3,500 ballots exhausted, showing that the method doesn’t always result in a majority winner.

Michael Shepherd

Michael Shepherd joined the Bangor Daily News in 2015 after three years as a reporter at the Kennebec Journal. A Hallowell native who now lives in Augusta, he graduated from the University of Maine in...