Ranked-choice voting to the rescue?

Democratic candidates for the Third District congressional seat during a debate in Lowell on April 29.Keith Bedford/Globe StafF

How’s this for ridiculous: Lori Trahan apparently won the agonizingly close Merrimack Valley Congressional Democratic primary, despite recording only 21.6 percent of the vote. The second-place finisher, Dan Koh, who was considering his recount options on Wednesday, finished 52 votes behind, according to unofficial results.

Bottom line: The Third Congressional District’s Democratic nominee won with less than one-quarter of the primary electorate. More than 40,000 voters supported one of the other eight candidates.

It’s hard to imagine a better advertisement for ranked-choice voting than this race, which featured an unusually diverse, high-caliber field. In a ranked-choice system, voters mark a first choice, a second choice, and so forth. If a candidate earns more than 50 percent of first-choice votes, the election is over. But in a case like the Third District, where no candidate reaches a majority, the candidate with the fewest first-choice votes is eliminated, and his or her votes are redistributed according to the second choices voters marked on their ballots, until a candidate hits 50 percent.

Bills to permit ranked-choice systems died in the Legislature last session, but lawmakers should see those 40,000 voters as a constituency for change. Advocates plan to reintroduce the proposals in the next legislative session, and they deserve attention. Like weekend voting and a spring primary date, it’s an electoral reform that would revitalize democracy in Massachusetts.

No voting system is perfect: Ranked choice can be confusing and, under certain circumstances, may hurt minority candidates for whom block voting in crowded races can be an asset. But it also encourages less negative campaigning, since candidates have an incentive to be voters’ second or third choice.

It’s no knock on Trahan, who earned her apparent win. But a more satisfying result for voters — and the candidates — would have been a system that gave them a better way to signal their preferences with such a large and talented field.