Maine’s voters took an extraordinary step during last year’s November election, passing a referendum that would make the state the first in the nation to use ranked-choice voting for statewide elections.

Under this voting system, voters rank candidates on their ballot instead of just voting for one. If no one gets a majority of votes in the first round, next-preference votes are counted until a candidate gets most of the votes. Several U.S. cities currently use ranked-choice voting, which both eliminates the “spoiler effect,” helping minor party candidates, and ensures that no one can be elected without the support of the majority of the voters.

But the state’s Supreme Court earlier this year issued a non-binding opinion that parts of the referendum law violate a provision of Maine’s constitution that allows statewide officers to be elected by plurality. The court, notably, did not state that using ranked-choice voting for primary and congressional elections would violate the constitution.

The issue was kicked to Maine’s legislature, which could make the technical fixes needed to make the law constitutional.

Last week, the legislature took the unusual step of delaying the law’s execution until 2021. Republicans largely supported the delay while Democrats were split. Independents opposed it.

Lawmakers will have until the 2022 elections to amend the law to make it constitutional or else face a full repeal. The vote was widely interpreted in the state as an attempt by the legislature to kill the measure.

The state’s current governor, Republican Paul LePage, first took office in a three-way race in which he got only a plurality of the vote in a contest against Democratic and independent candidates. Last year’s ballot initiative was, in part, a response to his election.

The campaigners who successfully convinced voters to support ranked-choice voting last year are not giving up. Four days after the legislature’s vote, the Committee for Ranked Choice Voting Maine, or RCV Maine, submitted an application to the secretary of state to trigger what is called a “people’s veto.”

The people’s veto is a Maine-specific procedure that allows voters to authorize a referendum to overturn laws recently passed by the legislature. In order to trigger the veto, campaigners must collect 10 percent of the votes cast in the most recent gubernatorial election. In this case, that’s 61,123 valid signatures. The tricky part is that the law requires that these signatures be collected and submitted within 90 days of the adjournment of the legislature — which gives RCV Maine until about early February to get it done.

Kyle Bailey, RCV Maine’s campaign manager, told The Intercept that the group is aiming to get enough signatures by the end of this year.

If they succeed, voters will use ranked-choice voting in Democratic and Republican primaries for congressional races and the governor’s race in June 2018. They will also use the people’s veto to weigh in on whether to continue using the ranked-choice voting system. Bailey believes being able to try out the new voting system will make it more popular. “I think voters exercising more voice and more choice by having the power to rank candidates will only intensify their support for this electoral change,” he said.

Diane Russell, a former Democratic state representative and a 2018 gubernatorial candidate, supports the veto drive. “We are doing everything we can to have petitions on time for Election Day, but we will not know for some time,” Russell wrote on Facebook. “We will keep you posted.”

Maine voters have used the people’s veto 29 times between 1910 and 2010. Most recently, the veto referendum was used to overturn a tax reform law.