WHEN JESSE MERMELL gave her videotaped concession speech in the 4th Congressional District primary race on Friday, she did it in front of a sign that read “Jesse Mermell for RCV,” an acronym for rankedchoice voting. “If the rankedchoice voting campaign needs a new face, give me a call, guys,” Mermell said. “I’ve got some time on my hands.” 

Mermell, a progressive who worked for former Gov. Deval Patrick, lost the Democratic primary by just 2,000 votes, or 1.3 percent, to Newton City Councilor and US Marine Corps veteran Jake Auchincloss. That means primary voters in the liberal congressional district that repeatedly reelected Joe Kennedy, Barney Frank, and Robert Drinan over the past five decades have selected seemingly the most moderate of seven Democratic candidates vying to represent them in Congress.  

Auchincloss, who worked for Republican Gov. Charlie Baker’s gubernatorial campaign in 2014, won in a seven-candidate field comprised mostly of liberals. Auchincloss rejects the “centrist” label and calls himself pragmatic progressive.”  But his close election reflects a campaign that performed strongly in much of the more moderate southern part of the 4th Congressional District, which extends from Brookline and Newton to Fall River, and featured a crowded field that likely led liberal voters to split their vote.  

The race is calling renewed attention to a November ballot question that would implement rankedchoice voting, which lets voters select candidates in order of preference and could mitigate the effects of vote-splitting. 

Evan Falchuk, chairman of the rankedchoice voting ballot committee, who personally supported Auchincloss, called the 4th District race “the poster child for ranked choice voting.” “You had seven really good candidates to choose from and, unfortunately, because of the current plurality system the winner ends up with 23 percent of the vote,” Falchuk said. Auchincloss got 22.4 percent of the vote and Mermell 21.1 percent.  

It’s hardly the first time a congressional candidate has won a crowded primary in the state with barely fifth of the vote. Rep. Lori Trahan narrowly won a 10-way Democratic primary two years ago for an open seat representing the Merrimack Valley with 22 percent of the vote, former congressman Michael Capuano also topped a 10-candidate field for the Boston-based seat he held for 20 years, garnering just 23 percent of the vote, and Sen. Ed Markey landed the House seat he held for more than three decades by prevailing in a 10-way primary with 22 percent of the vote. 

Falchuk said he could not predict if the outcome the 4th District primary would have been different with rankedchoice voting, but he does think the race would have included less negative campaigning, since candidates would not want to diminish their own likeability.  

Rankedchoice voting is a method in which voters rank candidates in order of preference. If no candidate wins a majority based on first-choice votes, the last-place candidate is eliminated and the voters who supported them have their votes distributed to their second-choice candidate. The process continues until one candidate wins a majority. Part of the argument for ranked-choice voting is that it avoids a situation where voters favor two similar candidates who split the vote, electing a candidate who appeals to fewer people. 

Both Auchincloss and Mermell support rankedchoice voting, but declined to say how they think it would have impacted their race.  

“I don’t have a crystal ball about what it would have done to this election, but certainly I think that we need to make sure we have rankedchoice voting going forward,” Mermell said Thursday. 

Auchincloss on Friday affirmed his support for rankedchoice voting, but said he would not speculate on its potential effect on his election. “I think trying to get inside of voters’ heads and calculations is an unfortunate practice,” Auchincloss said. 

In the last weeks of the campaign, two candidates in what had originally been a nine-way field – tech entrepreneur Chris Zannetos and former White House speechwriter Dave Cavell – dropped out, and both endorsed Mermell. Cavell said explicitly that he wanted to avoid splitting the liberal vote and allowing the more conservative Auchincloss to prevail. Because of early voting, thousands of voters already cast ballots before they dropped out and between them, Zannetos and Cavell got around 7,000 votes. 

Zannetos said he withdrew because internal polling showed no path to victory. Zannetos said he “absolutely” wishes he had dropped out earlier, but he does not know what impact that would have had on the field. 

Also running were Newton City Councilor and former Middlesex County prosecutor Becky Grossman; Alan Khazei, co-founder the national service organization City Year; former Wall Street regulator and democratic socialist Ihssane Leckey; epidemiologist Natalia Linos; and attorney Benjamin Sigel. Grossman got 18 percent of the vote, Linos and Leckey each got around 11 percent, Khazei got 9 percent, and Sigel less than 2 percent. 

Even on Election Day, some voters were concerned about the size of the field. “My greatest concern is with a large field we could end up with a congressperson who is not really representative of the district,” said Doris Brodhead, 61, a Newton voter and stay-at-home mom who supported Mermell. 

Jeffrey Berry, a political science professor at Tufts University, said a race with fewer candidates – or with ranked choice voting – certainly could have had a different outcome. Had Mermell gone against Auchincloss one-on-one it might have been a different election because all the candidates except Auchincloss were a shade of liberal progressive,” Berry said. “Overall, opinion along the ideological spectrum of 4th District voters is one skewed heavily toward the liberal progressive side, so it might have made a difference.” 

Maurice Cunningham, an associate professor of political science at the University of Massachusetts Boston, said similarly, “In a divided field where there were nine candidates, though two dropped out, and most were leaning a little more liberal, it raises the question of how representative the outcome is.”  

“The perception Auchincloss was the most conservative candidate of those in the race…raises issues of whether in a rankedchoice system Mermell would have been able to overtake him,” Cunningham said.