PORTLAND (AP) — A comment during supreme court arguments on ranked-choice voting offers a window into where many fear that things are headed — more legal challenges.

Justice Donald Alexander questioned whether the system that lets voters rank candidates could violate the “one man, one vote” principle.

His colleagues suggested that’s an argument for later. The court is currently considering other constitutional questions.

But his suggestion underscores critics’ worries that more lawsuits will be filed if the voting system is used in the June 12 primaries.

“The brief exchange indicates the expectation, or fear, that the case will come back after an election because the loser will probably try to get it overturned,” said Jim Burke, professor at the University of Maine School of Law.

The voting system under consideration would allow Mainers to rank candidates on the ballot in order of preference. A candidate with a majority of votes wins. If there’s no majority, the last-place candidate’s second-place votes are reallocated to remaining candidates.

It’s that reallocation Alexander referenced during a hastily convened session last week. He suggested the system would allow the supporter of a last-place candidate to effectively vote twice, violating the Equal Protection Clause.

But that’s not the issue before the court, Chief Justice Leigh Saufley said.

The court is currently considering an 11th-hour intervention by the Maine Senate, which contends the secretary of state is violating separation of powers by proceeding with ranked-choice voting without a specific funding directive from lawmakers.

Ranked-choice voting is in use in more than a dozen U.S. cities. It’s also been used once in a statewide election in North Carolina.

But its adoption in Maine has been messy.

Voters approved the system in 2016, but state lawmakers delayed implementation. Supporters then collected signatures to temporarily halt the delay pending a second statewide vote June 12.

Meanwhile, a previous Maine Supreme Judicial Court advisory opinion led to ranked-choice voting being limited to primaries and federal general elections.

Republican Sen. Roger Katz, of Augusta, said the Maine Senate will follow the supreme court’s guidance when it comes to the June primaries. But he said he remains concerned that confusion at polling places could reduce people’s confidence, and there could be costly lawsuits.

Supporters are nonplussed by the chaos.

Kyle Bailey, spokesman for the Committee for Ranked Choice Voting, said he wouldn’t be surprised if there are further political and legal efforts to undermine the voting system. He predicted those efforts will fail.

“Opponents of ranked-choice voting have gone through some great lengths to stop it from being implemented,” he said. “They’ve underestimated the will of the people.”