PORTLAND, Maine (AP) — Ranked choice voting will be used for the first time in a presidential race in the U.S. under a ruling Tuesday by the Maine Supreme Court, which concluded that a GOP-led petition drive intended to prevent its use came up short.

The Supreme Judicial Court concluded the Maine Republican Party failed to reach the threshold of signatures needed for a “People’s Veto” referendum aimed at rejecting a state law that expands ranked choice voting to the presidential election.

“This is a powerful moment for ranked choice voting supporters: Voters will, for the first time, use ranked choice voting to elect the highest office in the country,” said Rob Richie, president and CEO of FairVote, which advocates for the voting reform.

The court’s decision, just six weeks before the election, was issued after the state already began printing ballots using a grid-style for ranked elections.

“As we have already printed the ballots, due to the federal deadlines we must meet to provide ballots for overseas and military voters, this decision comes as a great relief and avoids the complications, confusion and expense that would have arisen from reprinting and reissuing ballots,” said Secretary of State Matthew Dunlap.

Under the voting system, voters are allowed to rank all candidates on the ballot. If no one wins a majority of first-place votes, then there are additional tabulations, aided by computers, in which last-place finishers are eliminated and votes reallocated based on those supporters’ second-place choices. Transporting the ballots to Augusta for additional tabulations delays results for about a week.

In Maine, the presidential ballot will feature five names, including Republican President Donald Trump and Democratic challenger Joe Biden. Ranked voting will also be used in U.S. House races and the closely watched U.S. Senate race between Republican incumbent Susan Collins and Democrat Sara Gideon, the Maine House speaker.

The voting system adds another wrinkle to the presidential contest in Maine, which — as one of two states that divide electoral votes — already does things differently.

In the last presidential election, Democrat Hillary Clinton won three electoral votes while Trump won one electoral vote in the 2nd Congressional District, underscoring political divisions between the state’s liberal, urban south and conservative north.

The ranked choice voting system, approved by Maine voters in 2016, has become a partisan issue in the state, where Republican U.S. Rep. Bruce Poliquin was ousted in 2018 despite collecting the most first-place votes.

Supporters say the ranked choice voting system eliminates the impact of so-called “spoiler candidates” and produces a majority winner. Critics say it’s unnecessarily complicated and disenfranchises voters who don’t understand it.

The constitutionality of the voting system has been twice upheld by a federal judge in Maine. However, ranked voting is not used in the governor’s race or legislative contests because it runs afoul of the Maine Constitution.

The fast-paced, 11th-hour legal machinations resolved Tuesday followed the secretary of state’s rejection of the referendum, ruling the GOP fell short of the needed level of 67,067 signatures of registered voters to force a referendum. The Maine GOP had appealed that decision and a state judge reinstated enough signatures to surpass the minimum by 22 signatures.

The issue before the state Supreme Court focused on a narrow question of whether signature gatherers must be registered to vote in the town where they are circulating petitions at the time they started.

The Supreme Judicial Court ruled unanimously Tuesday that the requirements don’t violate First Amendment rights of signature gatherers. That conclusion invalidated 988 signatures, delivering a defeat to the GOP.

But the Maine GOP wasn’t yet conceding on Tuesday. The party is “exploring further options for review by the federal courts to protect Maine voters’ rights to be heard,” its chair, Demi Kouzounas, said.

Anna Kellar, executive director for The League of Women Voters, which supports the voting reform, said the court’s decision is a victory for “every Mainer who sat around kitchen tables and in basements years ago, wondering how we could ensure more votes would be heard in our elections.”