FALMOUTH — Maine’s highest court issued an advisory opinion Tuesday that the ranked-choice voting act approved by voters last November is unconstitutional.

The court’s action sent lawmakers scrambling to decide what to do next.

State Sen. Cathy Breen, D-Falmouth, said she plans to submit a bill to amend the state Constitution to allow the use of ranked-choice voting in state elections going forward.

“Voters approved ranked-choice voting because they’re tired of politics as usual,” Breen said in a press release. “They want a better way forward, one that’s less partisan and more inclusive. By amending the Maine Constitution, we will preserve the will of the voters.”

In its opinion, which was requested by the state Senate, the Supreme Judicial Court defined ranked-choice voting as “casting and tabulating votes in which voters rank candidates in order of preference. Tabulation proceeds in sequential rounds in which last place candidates are defeated and the candidate with the most votes in the final round is elected.”

In early March, Maine Attorney Janet Mills also found that ranked-choice voting violates the provisions of the state Constitution, which says the winner of elections is chosen by a plurality.

“As a supporter of ranked-choice voting, I personally find this decision disappointing,” House Speaker Sara Gideon, D-Freeport, said in a statement Tuesday.

“I respect the opinion issued from the court,” Gideon said. “I will work with my colleagues in the Legislature to address the issues (because it’s) imperative that we move quickly in order to remove any uncertainty in our electoral process.”

The interest groups that campaigned for the ranked-choice voting option said in a joint statement, “The Maine Legislature must honor the will of the people and implement the law.”

Kyle Bailey, manager of the Yes On 5 campaign, added, “The Maine Legislature can act in response to the opinion of the justices to update the (state) law and they should do so.”

Bailey noted ranked-choice voting was approved “by the second-largest referendum vote of the people in Maine’s history.”

“Maine people believe that our system is broken (and) ranked choice voting is a critical solution to give more voice and more choice to voters in our elections and in our democracy,” he said.

Another supporter, former state Sen. Richard Woodbury of Yarmouth, agreed and said, “The reasons people passed the ranked-choice voting law are as urgent today as they were yesterday.”

“We’re counting on the Legislature to pass a constitutional amendment to fulfill the will of the people,” Woodbury added.

But while supporters of ranked-choice voting bemoaned the Law Court’s decision, the Maine Republican Party said in a press release, “This referendum sought to use the popular vote to override our Constitution and undermine the civic spirit and traditions of Maine’s elections.”

“I am pleased by this ruling, but disappointed in the resources that were wasted fighting faulty, special interest-driven legislation,” Jason Savage, executive director of the state Republicans, said.

“While liberals in Augusta continue to use the ‘will of the voter’ via referendum as a justification for poorly designed or damaging laws, we believe it is the job of the Legislature to protect the Constitution, our economy, and the well-being of our people and systems of government,” Savage said.

The finding of unconstitutionality for the  ranked-choice voting act only impacts statewide elections for governor and the Legislature.

The Law Court said under the state Constitution, it’s clear the only approved method for counting ballots is for it to be done by “municipal officials” and “the winner of each electoral race is the candidate who received a plurality of the votes cast and counted at the municipal level.”

In enacting the ranked-choice voting act, the justices said it would not only conflict with the Constitution of Maine, but it would also “fundamentally change the role of city and town officials in sorting, counting, declaring and recording votes.”

Whether ranked-choice voting is constitutional “goes to the very heart of our form of government, rooted as it is in the means by which the people may elect their chosen representatives,” the Law Court said.

Kate Irish Collins can be reached at 710-2336 or kcollins@theforecaster.net. Follow Kate on Twitter: @KirishCollins.

Members of the Committee for Ranked Choice Voting submitting petitions to force a referendum last year.